In this paper a Compatible Selective Harmonic Elimination (CSHE)-PWM is designed for three-leg four-wire (3L/4W) Neutral Point Clamped (NPC) inverter. The proposed CSHE-PWM is capable of eliminating both triplen and non-triplen harmonics from phase voltages and empowers 3L/4W NPC to handle both single/three-phase and linear/nonlinear loads. It has been mathematically proved that DC capacitors self-voltage balancing is achieved thanks to direct control of phase voltage waveform symmetry. Moreover, the cancellation of specified triplen and non-triplen orders has the advantage of having low capacitors voltage ripple. Therefore, the applied technique not only helps removing one leg of the inverter that reduces associate complex calculations and switching losses, but also directly controls phase voltage harmonic profile compared to SHE-PWM for four-leg four-wire (4L/4W) NPC. CSHE-PWM is practically tested on a NPC inverter prototype to validate the efficient harmonic elimination from the phase voltage waveforms along with capacitors voltages balancing under symmetrical/asymmetrical loads.

Four-wire configurations are commonly used in residential microgrids, where single-phase and nonlinear loads introduce harmonics, third-harmonic currents, and negative-sequence components. These harmonics often circulate within delta loops formed by line conductors, while negative-sequence currents cause power imbalance. In wind energy-based microgrids with transformers, such harmonic and unbalanced currents are often reflected into transformer or grid, leading to overheating, increased losses, reduced active power transfer ability, and possible failure. Processing these harmonic currents through transformers to prevent grid contamination demands a higher-rated neutral conductor, adding cost and thermal stress. To address these challenges, this work proposes a three-phase four-wire topology with an auxiliary converter at load point of common coupling (PCC), supported by a solar photovoltaic (SPV) array and battery energy storage (BES). Four-leg auxiliary converter compensates for load harmonics, neutral currents, negative-sequence components, and reactive power, while enabling power exchange from SPV array and BES units. It operates in both grid-forming and grid-following modes to support seamless transitions between islanded and grid-connected states. Integrated multi-mode control ensures coordinated source operation and compliance with IEEE Std. 1547 during mode transitions. Simulation results validate system effectiveness across various modes, demonstrating substantial improvements in power quality and operational reliability in residential microgrids.

This paper presents a novel design and optimization methodology for hybrid-dual rotor permanent magnet synchronous machines (HDR-PMSMs) featuring a double-sided stator structure. The machine comprises two distinct rotor types, positioned with an offset angle relative to one another, which enables maximization of torque density. Consequently, the presence of numerous design variables on each rotor side significantly increases the complexity of the design and optimization process. To address this challenge, a combined strategy involving magnetic circuit decoupling (MCD) and waveform targeting surrogate modeling (WTSM) is adopted to facilitate multi-objective optimization. As part of the MCD approach, a set of analytical equations is developed to predict the magnetic flux density in the stator yoke. It is demonstrated that, under unsaturated conditions, the HDR-PMSM can be decoupled into two independently modeled rotor systems, effectively simplifying the overall optimization problem. Furthermore, the WTSM framework reduces the number of finite element (FE) simulations required to identify optimal designs. The effectiveness of the proposed method is validated through a multi-objective optimization process, targeting improvements in average torque, torque ripple, and permanent magnet (PM) volume, while ensuring safe magnetic operation through the consideration of anti-demagnetization constraints.

The voltage level multiplier module is an emerging class of compact power electronic topologies that aims to maximize the power quality and conversion efficiency using minimum active and passive components. The promising merits of voltage-level multiplier module inverters (VLMMI) render them ideal for integrating renewable energy into microgrid environments. This paper presents a new intelligent direct power control (IDPC) technique for grid-connected VLMMIs to control the power flow directly through a distributed energy resource management system (DERMS). Furthermore, a robust control algorithm is developed using sliding mode control theory to regulate and stabilize the voltage and current of the VLMMI in the grid-connected mode of operation. Preliminary simulation results confirm that the proposed IDPC supported by the robust controller allows VLMMIs to effectively operate in microgrids and accurately respond to a DERMS.

This paper presents the air gap flux measurements during the establishment of the open circuit saturation curve, and load ramp-up of large hydro electrical generator. Experimental data were carried out on three different machines tested at different operating conditions. The advantages, disadvantages, and limitations of the rotor windings diagnostic using the voltage induced by the pole leading edge instead of using the magnetic flux value is analyzed and discussed. New diagnostic features to detect interturn short circuit inside the rotor windings are also introduced.

Community and residential loads connected to low voltage AC distribution networks require a neutral point connection. Neutral point forms return path for single-phase loads. Presence of neutral wire reduces effect of unbalanced loading of one phase to get reflected on other load phases. It helps during fault conditions to minimize effect of circulating current by providing low impedance path. However, in case of harmonically polluted load currents, rating of neutral conductor increases, leading to additional losses and unwanted heating effecting other components of network. Wind energy conversion systems (WECS) use transformer for connection to AC network to reduce requirement of higher rating and size of DC link capacitor. Neutral current and harmonic currents of load are processed through the transformer, which leads to additional heating of transformer ands which is detrimental for connected loads. Such conditions can lead to failure of WECS operation and damage transformer and connected sensitive loads due to flow of circulating currents. Hence, this work presents design and control of a novel four wire topology of a WECS comprising of a doubly fed induction generator (DFIG) and a battery energy storage (BES). A grid forming converter (GFC) is deployed to provide independent compensation for load neutral and harmonic currents without affecting the WECS transformer, reducing its failure and heating rate. WECS converters are controlled to improve power quality of stator current and point of common coupling (PCC) voltage as per the IEEE 519-2022 std. Simulation results present MPPT operation of WECS with neutral and harmonic compensation even during dynamic conditions.

The Internet of Energy (IoE) paradigm introduces new challenges and opportunities for efficient power routing in decentralized energy networks. A novel approach is implemented to enhance power routing efficiency within the IoE framework by integrating adaptive Q-learning techniques with a maintenance phase. The proposed distributed Self-Healing Protocol (SHP) utilizes discovered paths during the maintenance phase instead of recomputing a path to transmit a Power Packet (PP) in case of a fault. Our proposed Self-Healing Q-Learning Routing protocol aims to optimize energy delivery by dynamically adapting routing decisions and addressing system maintenance in real-time. This power routing protocol operates without centralized control, leveraging autonomous behaviors for system resilience and performance optimization. It covers all scenarios, including Multiple Source Single Load (MSSL), Multiple Source Multiple Load (MSML), and Single Source Multiple Load (SSML) scenarios. This approach is validated using MATLAB simulations.

In this study, a novel 7-Level Packed U-Cell (PUC) converter with Model Predictive Controller (MPC) for solar grid-tied applications is presented. The excellence of photovoltaic (PV) solar panels as an interface application in producing green power for utility is examined by the proposed topology. Our innovation represents a novel attempt to use PV solar panels incorporated with PUC converter in its two DC links rather than just one. The designed model's primary advantage is its overall reduced complexity design compared with other existing topologies. Hence, no additional controller other than MPC—such as a PI controller—is needed to extract grid reference current, Additionally, since the utilized Perturbation and Observation (P&O) technology directly controls the provided power, no DC-DC booster converter is needed while integrating PV solar panels to the PUC converter. To assess and verify the proposed concept's performance, Matlab/Simulink simulations were run. However, to verify the suggested topology's robustness and dynamic response, it was tested in steady state condition and under other various types of sudden disturbances. The system demonstrates resilience to changes in grid voltage, phase shift and irradiation.

In electrical equipment maintenance, precise diagnosis is critical for dependability and efficiency. Variational Autoencoder (VAE) approaches show promise for fault classification but encounter hurdles due to their non-deterministic nature, which results in inconsistent fault grouping across machines. To address this, a novel method incorporates a desirability function into the VAE’s cost function, resulting in standardized fault classification. This approach, evaluated with vibration data from large hydrogenerators, demonstrates that the enhanced model can cluster 86% of comparable faults into predefined zones, compared to 27% without including this term, while accounting for two severity levels of three rotor faults.

With reduced number of components count, Modular Multilevel Converter (MMC) based on ZPUC converter can generate a higher number of voltage levels when compared to well-known topologies. However, the capacitors voltage balancing of ZPUC topology remains a challenge when operating as a submodule due to the high number of capacitor’s voltages to be regulated at the same time in each submodule. This becomes more complicated when several submodules operate and when no self voltage balancing can be achieved such the case of seven-level ZPUC (7L-ZPUC) converter. For this reason, Model Predictive Control (MPC), well known of its superiority in achieving multiple control objectives and superior dynamic performance is introduced in this paper as a controller for the MMC converter based 7L-ZPUC. A Finite Set Model Predictive Control method (FS-MPC) is designed to control a three-phase grid-connected MMC. The proposed FS-MPC is designed to generate thirteen-level output phase voltage and 25-level line-to-line voltages. A detailed real-time model of the converter and its suggested controller is developed and implemented in the real-time simulation software Hypersim to validate the effectiveness of the proposed predictive control. Real-time implementation results verify and demonstrate the good performance of the overall Software In the Loop (SIL) application.

This paper presents a new topology for AC-DC grid-tie inverter in renewable energy application. The simple switch configuration is built around a filter-like energy storage cell to isolate and decouple the operation of the three half-bridges. The intra converter storage is built around the coupled inductor principle, allowing therefore for lower switching frequency, lower voltage stress and shared current across the components. The sequence of operation, along with the design and sizing of the circuit components will be presented before getting to the simulation results. The simulation results confirm that is new topology offers flexible and versatile behaviors and for the same components is more efficient than other topologies.

This paper develops a robust artificial intelligent controller for a compact multilevel converter to operate in grid-following and grid-forming modes without islanding detection. The proposed controller is designed using sliding mode control, a multilayer Perceptron neural network, and a unique supervisor to select the operation mode of the converter automatically. Compared with islanding detection-based control methods, a single unit controller is required, which is more robust against false trips. The simulation tests also confirm that this technique is highly accurate and only causes a non-detection zone when the load demand is equal to the peak power of the converter.

The nonlinear loads demean the system power quality leading to increased ohmic losses and shorter equipment lifespan. To mitigate power quality challenges, this work proposes a multiple delayed signal cancellation filter with 15 layers and unit delay factor (MDSC115) for improved power quality of a grid-tied solar power conversion system (SPCS) equipped with a battery energy storage (BES). The control attenuates all integral positive sequence harmonic components from 2ndto 30thharmonics excluding positive sequence 16thharmonic. It also eliminates integral negative sequence harmonic components from 1stto 28thharmonics excluding negative sequence 14th harmonic, including 0 Hz DC component, without the need of additional prefilters cascaded to the filter. A modified frequency locked loop (MFLL) is incorporated to make the MDSC115 adaptive to the varying grid frequency and make it immune to phase angle jump and frequency fluctuations in the grid voltages. The MDSC115-MFLL improves the power quality of SPCS during grid adversities and load current irregularities. Performance of MDSC115-MFLL is validated in MATLAB during several dynamic test cases and compared with other delay-based controls to ensure better performance and commitment to the IEEE std. 519 during operation of SPCS.

In this paper a micro-grid configuration is proposed to enhance battery charger of electric vehicle for residential household, V2G, V2V and V2H. The micro-grid configuration consists of a single phase seven level PUC, a single phase Dual Active H Bridge (DAB) and PV solar to support fast charging operation of EV batteries. A single phase seven levels acting as interface between different energy sources and acting as compensator for current harmonics and reactive power. A current Model Predictive control is adopted to take advantages of low switching function, easy to regulate both DC voltages through the cost function. A lower DC bus voltage is a great advantage which represents (2/3) of the Vdccompared to the maximum grid voltage. A Boost converter acts as solar controller to extract maximum power from the PV solar. A non-linear control approach is proposed for single-phase dual active bridge (DAB) to control the power through the phase shift angle to charge and discharge the battery of electric vehicle using constant current mode and constant voltage mode (CC/CV) to provide protection for the electric vehicle (EV) battery.

The concept of “system inertia,” “system droop,” and system frequency response to disturbances, are widely discussed and used to limit the frequency deviation in a microgrid. To remedy this, the concept of cascade droop-virtual synchronous generator (VSG) is increasingly integrated, based on the imitation of the very popular synchronous generator (SG), which enhances the inertia and damping of the system, making it robust with better frequency stability. The droop task estimates the active power needed to reduce the frequency deviation from the battery energy storage system (BESS) and the VSG controls the inverter through the PLL (Phase Locked Loop) angle to inject this active power at the PCC (Point Common Coupling). The proposed cascade droop-Vsgcombined is greatly improved with the power sharing using droop for the two diesel generators and the increase/decrease the transient voltage at the PCC during load variation and PV solar power transfer to the load. Finally, the simulation results obtained correspond to our expectations and demonstrate the viability of the approach, reducing frequency deviation, ensuring stability of the voltage at the PCC and improves power sharing.

This study looks at the challenge of parametric estimation in photovoltaic (PV) module with manufacturer information from the perspective of evolutionary computation. A non-linear non-convex optimization problem is created using the data sheet provided by the PV manufacturer, which includes information on maximum power, open-circuit, and short-circuit values. Comparative analysis is made between particle swarm optimization, artificial electric field algorithm, whale optimization algorithm, crow search algorithm, harmony search algorithm and a hybrid algorithm of PSO and pattern search for parameter extraction of a mono-crystalline Sanyo-HIT215 solar panel. The results are tabulated and I-V characteristics plotted.

A nine-level packed U-cell (PUC9) multilevel converter is introduced as a submodule of a modular multi-level converter (MMC) to increase the voltage level by reducing the component counts. This topology would handle the DC fault current without needing the additional DC circuit breaker. PUC9 topology doubles the output voltage levels at the output of MMC with 33% more component counts rather than PUC5. The proposed configuration could be operated as a single DC source single-phase or three-phase multilevel converter with the capability of modularity and scalability. Voltage balancing integrated with level shift pulse width modulation (LS-PWM) technique is applied to balance three flying capacitors (FCs) voltages of each submodule without needing to an external controller. To validate the performance of the converter in transient and steady-state mode, PUC9-MMC is modeled in Matlab-Simulink and the results illustrate the appropriate waveforms in stand-alone mode.

Modular Multilevel Converter (MMC) is a promising topology that gained lot of interest in medium-voltage grid-connected applications due to its modularity, scalability, and adaptability. Although increasing the number of submodules per arm leads to a higher number of voltage levels and better waveforms quality, the size and then the cost of the converter remains a challenge. Therefore, a trade-off between topology complexity and power quality exists. This paper proposes an MMC based on Z Packed U-Cell converter as Submodule (ZPUC-SM) to generate a higher number of voltage levels with reduced number of SMs. When compared to HB-MMC, this topology features reduced components count for generating the same voltage levels. Thus, the candidate topology is considered to be a promising solution for medium-voltage applications connecting the utility. This paper details the design, modeling and control of ZPUC-MMC operating as a three-phase grid-connected converter. The controller task is to regulate output current to fulfill grid connectivity requirements. A Phase shifted-PWM with an integrated voltage balancing algorithm takes in action of controlling the three-capacitors voltages of each arm. Thus, no additional voltage controllers are required. The performance of the proposed converter along with its control system are validated with MATLAB/SIMULINK, and the simulation results validate the robustness and effectiveness of the proposed control during both steady-state and dynamic operations.

Compact Multilevel Converters (CMLCs) as an emerging class of bidirectional Multilevel Converters (MLCs) offer the best trade-off between components count and power quality. Nonetheless, reducing the conduction passes as well as using minimum semiconductor devices cause reliability issues and impose maintenance costs, as voltage stress degrades the performance and lifetime of the components. Accordingly, this paper introduces a novel predictive form of voltage stress for semiconductor devices used in CMLCs to address the related issues. In the end, verification results provided through a grid-connected nine-level Packed E-Cell converter demonstrate the effectiveness of the proposed Voltage Stress-based Model Predictive Control (VSMPC) technique in dealing with voltage stress as well as tracking the other essential control objectives, simultaneously.

This paper investigates the effect of unintended island mode and load change on parallel inverters in a hybrid microgrid system. The power system consists of three voltage source inverters with different power ratings connected in parallel to the AC bus. Moreover, two DC/DC converters are connected to the DC bus. An interlinking converter (ILC) is used to achieve bidirectional power flow between the AC and DC buses. A virtual impedance-based droop controller is implemented achieve an accurate power-sharing between the inverters connected to the AC bus and a smooth transition between grid-connected and island modes. The main motivation behind the use of the virtual impedance is to overcome the problem caused by the mismatch of inverters’ impedances. In this regard, the performance of parallel inverters are evaluated under transient operation from grid-connected to island mode and considering load change. The results of numerical simulations confirm the effectiveness of the method and the capability of the virtual impedance controller to avoid the problem of impedance mismatch.

In this paper, the systematic design procedure of the proposed lead-lag direct power model predictive controller (L2DP-MPC) for active-front-end (AFE) rectifier is presented. First, the parametric design procedure of the linear proportional-integrator (PI) and lead-lag controllers are described. Then, in the lead-lag control system, the inner-loop current controller is replaced by the non-linear DP-MPC controller to form the proposed L2DP-MPC. Moreover, a comparative study between four designed controllers including the PI, lead-lag, PI-DP-MPC, and the proposed L2DP-MPC is performed from various aspects. All of the controllers are applied to the three-level active-neutral-point-clamped (3L-ANPC) AFE rectifier to evaluate the performance of each controller. The presented simulation results verify the performance, feasibility, and superiority of the proposed L2DP-MPC over the PI, lead-lag, and PI-DP-MPC methods.

In this paper, a new asymmetric multilevel inverter (MLI) topology proposed to avoid the drawbacks of using numerous DC voltage sources and H-bridge cells in asymmetric MLIs. This structure consists of two modules. The first module is a five-level neutral point clamped (NPC5) and the second module is a nine-level packed E-cell converter (PEC9) containing a few low-cost and low-size devices. These modules are connected to each other, and a hybrid PWM modulation is operated to result in the 41-level asymmetric inverter. The proposed hybrid PWM modulation causes to operate only five low voltage and low power switches at the switching frequency, while the rest of the switches operate at low frequency or at the fundamental frequency, which reduces the size and cost of the proposed 41-level inverter. The presented simulations by MATLAB SIMULINK confirm the suitable performance of the inverter as well as the proposed hybrid modulation method.

Wireless power transfer (WPT) system is a promising candidate for charging many electrical devices and daily home appliances. Most widely used WPT techniques are inductive coupling based on magnetic fields, and magnetic resonant inductive coupling, which include a resonant circuit in transmitter and receiver coils. In this paper, numerical and analytical analysis of short-range inducting coupling rectangular coils WPT is presented. A numerical methodology based on a three-dimensional discontinuous Galerkin time-domain (DGTD) finite element method is developed to estimate the electromagnetic propagation around WPT rectangular coils. The proposed approach leads to simulations that are fast, robust and accurate, this being the result of a local discretization strategy of the full-wave time-domain Maxwell’s equations on unstructured tetrahedral meshes that is easy to parallelize. The stability of the overall numerical scheme is obtained using an up-wind numerical flux, an implicit second-order accurate time integration scheme, and Whitney basis functions. The numerical methodology is verified based on problems with analytical methods.

Modular multilevel converters (MMCs) are a well-known solution in high-voltage applications. Recently, new topologies such as MMCs with series/parallel (MMSPC) connectivity are attracting large amount focus, due to their improved efficiency as well as self-balancing capability. Although MMSPCs can operate without direct measurement of modules’ voltages in battery-integrated modules, monitoring of the voltage and resistance of each module can still provide useful information to assess the state of each battery. However, including a voltage and current sensor in each module is not a cost-effective approach. This paper proposes a method to estimate the voltage and resistance of each battery-module using only the voltage and current measurement at load terminal. The proposed technique can reduce the number of sensors from 2N + 2 to only 2. Additionally, due to the self-balancing capability, the estimation technique does not require fast convergence and can operate in the background during the idling intervals of the processor. MATLAB simulations confirm the applicability of the proposed approach. The result show a 99 % and also 96 % accuracy for balanced and imbalanced systems.

In this paper a sensor-less voltage balancing algorithm integrated with phase-shift pulsed width modulation (PS-PWM) is proposed to reduce the size of the flying capacitor (FC) on Packed U-cell (PUC5) converter. The size of the flying capacitor that is achieved by proposed method is the least value heretofore. In conventional modulation methods charge and discharge of the FC is carried out in power frequency. In contrast, in proposed method this process is accomplished in carrier frequency. Increased frequency of FC with PS-PWM carriers leads to highly reduce the FC size. Moreover, all the benefits of Phase-shift modulation such as filters size reduction and total harmonic distortion (THD) reduction is achieved. The comparison between previous literatures and the proposed method is carried out in this paper to compare among the size of FC. Simulation is run by Matlab/Simulink to validate the performance of this proposed method on stand alone and grid connected mode.

This paper presents a grid-integrated multilevel inverter based on Packed E-Cell (PEC) structure for connecting renewable energy sources to the existing power grids. This dual source topology benefits from low number of semiconductor devices, simple robust control strategy, and smooth current of the capacitors. The shunt-capacitors of the converter are charged or discharged simultaneously to a quarter of the input DC source via horizontally extension design of the circuit. Thus, by applying only one voltage sensor and simple phase disposition pulse width modulation approach (PD-PWM), the operation of the inverter to generate 17-levels for the output voltage is ensured. For improving the dynamic performance of the converter, a closed-loop controller is designed and a precise mathematical analysis is presented as well. Accurate performance of the proposed structure is assessed by calculating theoretical analyses and simulating the inverter in MATLAB Environment.

The presented article introduces a versatile multilevel inverter based on Packed E-Cell (PEC) topology. This structure is suitable for conversion of photovoltaic energy generations to supply AC loads and uninterruptible power supplies (UPS). Requiring a reduced number of power switches and capacitors compared to other inverters along its control simplicity are the prominent merits of this converter. Thanks to the horizontally extension of the shunt-capacitors, both of them can be charged or discharged to a quarter if the input source, at the same time. Hence, by applying two isolated input sources and one voltage sensor, the proposed inverter generates 17-levels for the output voltage. Simple level shifted pulse width modulation technique (LS-PWM) is used to control the operation of the proposed inverter. Finally, the accurate performance of the proposed multilevel structure is investigated through MATLAB simulations.

In this work, the uninterrupted residential power supply is ensured by utilizing a resilient synchronization control for distributed generation based reconfigurable AC microgrid. The distributed generation from renewables such as photovoltaic array and wind power generation with energy storage is included. The power supply reliability is enhanced by utilizing a diesel generator (DG) as a back-up source for the instances of generation shortage from renewable resources and completely drained battery storage. The seamless operating modes namely current control and voltage control are enabled in accordance to the occurrence/clearance of the faults via the static transfer switches (STS-1/2) that isolate/reconnect the microgrid to the utility/DG. The high quality power is ensured by utilizing ε-normalized sign regressor least mean square (ε-NSRLMS) algorithm to evaluate the total current active component of loads. Modified notch filter based second order generalized integrator-frequency locked loop (MNF-SOGI-FLL) avoids frequency and phase oscillations and provides the effective frequency and phase synchronization. The output of the DG is controlled by the automatic voltage regulator (AVR) associated at the synchronous generator (SG) field terminals. The microgrid allows sensitive load operation, uninterrupted residential load supply and improved power quality and these are confirmed from simulation and experimental results obtained from the laboratory prototype.

In this paper, an adaptive fuzzy passivity-based control strategy is proposed to provide stable operation for a grid-tied nine-level packed E-Cell (PEC9) converter. Passivity theory is developed in the first step to enable the error dynamics of the PEC9 converter currents to reach a much more effective convergence rate using the proposed damping coefficients. Moreover, various operating margins are achieved for the damping coefficients through PEC9 current errors-based 3D curves. In order to establish online estimation for the damping coefficients, the fuzzy controller and Artificial Neural Network (ANN) are combined. Experimental and simulation results are employed to validate the accuracy of the proposed control technique under load variation, parameter mismatch and DC-link voltage variation.

Considering the vast application of Power Electronic Converters (PEC) in numerous modern technologies, modeling their behavior is of immense importance. These components are non-linear and modeling their precise behavior requires a relatively substantial amount of computational resources. In this paper, a modeling method based on Gated Recurrent Unit (GRU) networks is proposed that is capable of modeling PECs with the aid of machine learning. Furthermore, the precise datasheets of many commercial over-the-shelf converters are not readily available. Thus, the proposed method is a black-box modeling method that only requires the input and output signals of a converter to model its dynamic behavior. For a performance comparison, the proposed GRU-based method, as well as another similar method based on Long-short Term Memory (LSTM) networks, are used to model a voltage-regulated variable-load DC/DC buck converter. A detailed switching model of the aforementioned converter is simulated in Matlab/Simulink environment to generate the required datasets. This model is also used as a reference for comparison. Ultimately, both of the models are exported to Matlab/Simulink after training to be simulated and assessed.

This paper presents a direct non-linear based predictive control for a single-phase Shunt Active Power Filter nine-level Packed E-Cell inverter (SAPF-PEC9). The proposed control based on a Finite Set Model Predictive Control (FS-MPC) has been designed to compensate the reactive power requested by the nonlinear load at the Point of Common Coupling (PCC). An outer loop consisting of a PI regulator together with a low pass filter is used to regulate the main capacitor voltage and to inject the proper filter reference current. Meanwhile, the overall design is very simple where a very fast and robust controller is achieved. Moreover the nine-level converter operation together with the direct predictive approach allows the reduction of the passive filter at the shunt converter terminals. Hence a microscale filter is obtained. The performance of the proposed hybrid controller in reactive power compensation, harmonics suppression and unity power factor operation is investigated under stiff grid conditions (zero impedance) through both normal and dynamic load-change operation. Simulation results are provided to validate the fast and effective dynamic performance, the very low harmonic content in the mains current as well as the DC capacitors balancing of the PEC inverter.

In this paper a novel single dc-source switch-capacitor compact multilevel topology is designed based on Packed E-Cell to have the boosting potency for the 11-level operation and to merit as a reliable AC-DC converter for fault tolerant capability. The proposed single-phase compact converter is reduced the active/passive components counts while the output voltage levels are increased which it includes 6 normal power switches and 3 bidirectional switches as well as 2 dc capacitors as the auxiliary dc sources. While the conventional compact converter is incapable of fault tolerant operation, the proposed topology could emerge as a reliable while it has the boosting ability due to its switched-capacitor feature. Moreover, the dc capacitors are actively balanced thanks to various switching states redundancy. The proposed single-phase switched-capacitor converter is validated by theoretical analyses as well as simulation results obtained by Matlab-Simulink where it shows the accurate dc capacitors voltages balancing and prefect 11-level generation in the AC output terminal.

This paper deals with the power quality improvement in a solar photovoltaic (PV) array generation-based EV (Electrical Vehicle) charging station. This charging station is capable of operating in standalone mode and charging the EV battery with the power generated by a PV array. Moreover, it also interfaces with the utility and feeds it the remaining power. Another advantage of the charging station is the compensation of the reactive power for the improvement of the grid power quality. The charging station serves the following purposes (i) harmonics current compensation, (ii) EV battery charging/discharging control, (iii) simultaneous EV battery charging and harmonics current compensation and (iv) simultaneous discharging and harmonics current compensation. The charging station is controlled in such a manner that it operates satisfactorily even under the unbalance grid voltages and total harmonics distortion of the grid currents is reduced below 5% as suggested in the IEEE-519 standard. The control strategy is designed in such a manner that the charging station operates in grid connected mode. However, if the charging station loses the synchronism, then it operates in standalone mode and PV array charges the EV battery. A synchronization control is also developed to connect the system to the grid, when it is available.

In this paper, a switching function based-equivalent model of the paralleled modular active-neutral-point (PM-ANPC) multilevel converter with decoupled DC link is proposed. The development of this equivalent model is motivated by desire to perform hardware-in-the-loop (HIL) tests of a battery charger based on the PM-ANPC and by the stringent computational requirements of real-time simulation. Consequently, the power semiconductors are replaced with voltage sources controlled by switching functions, and this simplified model aims to emulate a reference model based on switching devices. Moreover, the proposed model minimizes errors caused by measurement delays and improves the overall simulation performance. These results are confirmed in Simulink where comparative tests are performed between the equivalent model and the reference model for both offline and real-time simulation. The simulation results demonstrate that the proposed model is capable to accurately emulate the reference model while offering improved simulation performance.

Modular multilevel converters (MMC) show great potential in high-voltage as well as emerging applications such as grid storage and electro mobility. The main advantages over the two−level converters include flexibility, scalability, and higher degrees of freedom. MMCs with series/parallel connectivity (MMSPC) are a more recent developed technology which can provide stable and efficient sensorless operation. However, although the additional parallel connection between the modules provides many advantages, it can change the equivalent resistance of the system and hence complicate the power loss analysis. This paper presents a simplified conduction loss calculation method based on equivalent resistance analysis for MMSPC. The presented method has the advantage of simplicity with relative accuracy that can speed up the process of loss analysis. Simulation results show that the accuracy of the presented method is above 95% percent for modulation indices above 0.5.

An accurate reference current detection (RCD) algorithm with the ability of double-frequency oscillation cancellation (DFOC) is designed in this paper to control a nine-level packed E-cell (PEC9) as a single-phase active power filter (SPAPF). The reference current is detected through DFOC-based RCD and subsequently injected by the converter. The detected current contains all unnecessary components and is accurate enough to keep the grid current in sinusoidal form with the THD under the permitted threshold. The proposed PEC9-based SPAPF not only guarantees the power quality at the grid side, but also benefits all advantages of PEC multilevel converter. The effectiveness of the proposed SPAPF is assessed in comparison with conventional one and its performance is investigated via simulation studies by using MATLAB/SIMULINK software.

This article proposes a passivity method synthesized by an adaptive neuro fuzzy inference system (ANFIS) to control a grid-tied nine-level packed E-cell (PEC9) inverter. PEC9 is an optimized components count of single-phase, single-dc-source, compact multilevel converter with an appealing feature of dc capacitors horizontal extension. Indeed, PEC9 forms a single auxiliary dc-bus to actively balance its voltages so as grid-tied controller would not be charge of capacitors voltages balancing. Hence, the proposed intelligent-based passivity control (IPC) is designed using only the dynamical model of the PEC9 inverter current. The zero dynamics of state variable errors are obtained and a damping coefficient matrix is presented to theoretically analyze the convergence rate of PEC9 inverter currents under the proposed control functions. In addition, various operating margins of damping coefficients are inquired. So, using the margins, a trained ANFIS as an online estimator tracks the damping injections. It precisely regulates the damping coefficients in unstable conditions; thus, the excellent PEC9 inverter operation is guaranteed. Experiments and simulations validate high reliable performance of the proposed IPC technique under various grid-tied operational conditions.

In this paper, a simple space vector modulation called 1D-SVM integrated with an active capacitor voltage regulation algorithm is applied to the appealing single-phase single DC source nine-level (PEC9) inverter. The proposed 1D-SVM reduces the switching losses by avoiding the additional switching in the middle of defined switching period and also provides the better capacitor voltage regulation compared to carrier based methods. Additional switching could be imposed when the carrier base methods integrated with the capacitor voltage regulation algorithm in PEC9. But, the proposed modulation technique not only prevents the additional occurrences but also decreases the ripples of the capacitors voltages so it can decrease the size of the capacitors. The 1D-SVM calculates and determines a duty cycle for the whole single-phase multilevel converter in each sampling time. The performance of the proposed 1D-SVM for the PEC9 capacitor voltage regulation has been investigated by simulation tests in Matlab-Simulink environment.

In this research, double space vector pulse width modulation is used to control the dual stages of the indirect matrix converter. This modulation technique is facilely comprehended and simply put into real-time practice. An experimental prototype of the indirect matrix converter is developed. The modulation algorithm is implemented on a digital signal processor. After establishing the duty ratios and the modulation signals, the gate drive signals are formed and sent to the semiconductor devices. Keen analysis of the overall system and the overall consolidation of topology, modulation, and drive implementation is presented.

Reducing the computational burden and improving the accuracy are in the two opposite sides of every electrical equivalent circuit model (EECM) for batteries. In this paper, a novel identification method is developed to estimate EECM parameters for any Li-ion battery with the aim of reducing computational burden and improving the accuracy of estimation under high C-rates of charge/discharge cycles for electric vehicle (EV) applications. The proposed parameter identification method is implemented on the second-order EECM. A step by step execution of the new identification method is presented which is based on circuit analysis and Particle Swarm Optimization (PSO). A comparison is carried out between obtained and the Pseudo-Two-Dimension (P2D) electrochemical model results. Moreover, experiments are carried out on two Li-ion battery cells, NCR18650 Panasonic and Mp176065 to verify the accuracy of the proposed method. The included results demonstrate the performance of the proposed method regarding improving accuracy and applicability as well as reducing required memory.

Z packed U-cell (ZPUC) is a novel generalized topology of multi-level converter which is appropriate to generate numerous voltage levels through single DC source. This topology is located as a submodule in modular multilevel converters (MMCs) aimed to increase the voltage levels and voltage stress reduction in switches simultaneously. Voltage balancing integrated with phase shift pulsed width modulation (PS-PWM) strategy without using external control system is employed in this paper to balance the voltage of flying capacitors (FCs). Matlab- Simulink is employed to simulate the ZPUC converter in three- phase system in stand-alone and grid connected mode. In addition, experimental tests are implemented on a 3 kVA prototype of ZPUC topology to validate the performance of the converter.

In this paper, a bidirectional power electronics converter assisted by Photovoltaic Panels for Electric Vehicle battery charging application is presented. The charger is composed of two conversion stages: an AC/DC converter represented by an active-rectifier, and a DC/DC converter illustrated by a Dual Active Bridge. The solar renewable energy is considered an alternative DC source assisting in charging the battery. The charger is tested using MATLAB/SIMULINK under different charging and discharging scenarios. An Electric Vehicle equipped with a bidirectional battery charging system has the ability to act as source or a load.

The presence of nonlinear loads challenges the power quality regulation in stand-alone and grid-connected converters. Employing bulky passive or active filters is common to filter out the harmonics; but this is a costly solution. In this paper, an Intelligent Harmonic Suppressor (IHS) using fuzzy control theory and Second Order Band Pass Filter (SOBPF) is proposed to mitigate the harmonics caused by unknown nonlinear loads in a stand-alone nine-level Packed E-Cell (PEC9) inverter. PEC9 is a promising multilevel topology which can generate a quasi-sinusoidal voltage waveform only by a single dc source. In the proposed IHS technique, PEC9 is forced by the fuzzy controller to track the desired current reference that is provided by an adaptive control law based on the load impedance. Simulation results verify that since the undesired harmonics emerge in the measured signals applied to the control loop, using SOBPF before the fuzzy control inputs notably reduces THD while the references for the load current and the auxiliary dc capacitors voltages are accurately tracked.

This paper presents a Multi FPGA- based solution for More Electric Aircraft power systems real-time simulation. The proposed solution allows control and protection devices to be designed and tested in virtual power system before they can be implemented in a physical system. To demonstrate the effectiveness of the multi-FPGA solution, a model approximately representing the Boeing 787 More Electric Aircraft is considered. The B787 power system represents a challenge for any real time simulator. It includes a considerable number of fast and slow switching frequency converters, an extensive number of circuit breakers and very short cables that complicates the power decoupling task.Four complete feeders of the B787 power system are simulated using Dual-Kintex-7 FPGA boards. The controllers and mechanical parts of the Motorized Turbo Compressors are compiled, and real time simulated using a 3.5 GHz Intel processor. The performance of this overall Processor-In-The-Loop integration (PIL) is validated based on two criteria: 1) Evaluation of the results accuracy compared to the reference offline simulation. 2) Evaluation of the numerical stability of the simulation under steady state and fault conditions.

Transformerless single-stage Current Source Inverter (CSI) is a very promising power electronic converter due to its inherent boost capability and ease of control. This paper investigates the performance of two traditional CSI topologies with different switch count (conventional six-switch CSI and seven-switch CSI7), for grid-connected Photovoltaic (PV) applications. Both topologies are controlled using the Space Vector with Pulse Width Modulation (SVPWM) technique. The performance of the proposed topologies are assessed by means of numerical simulations and the results are compared in terms of Common Mode Voltage (CMV), ground leakage current, and injected grid-current harmonic distortion THD. Furthermore, conduction and switching semiconductor power losses are computed and simulated over a grid period. Simulations are carried-out at different operating points of the converter to evaluate the performance of both topologies for grid-connected PV applications. The obtained results prove that the CSI7 topology strongly reduces the fluctuations of the CMV and, therefore, results in lower ground leakage current. It also allows the injection of high quality currents with lower THD into the power grid and, commonly, reduces power losses in power semiconductors. With respect to conventional CSI, the CSI7 topology offers high performance criterion and increased efficiency at the cost of one additional power switch.

In this paper, a microgrid based on solar photovoltaic (PV) array and a battery energy storage (BES) is presented, which operates in an islanded mode and the grid connected mode. It changes the mode of operation seamlessly, while supplying uninterrupted power to the load. A cascaded SOGI (Second-Order-Generalized-Integrator) based control is used in GCM. The cascaded SOGI is used to extract the fundamental component of the nonlinear load current. A PV array power feed-forward component is used for improving its system dynamics. An optimal power from the solar PV array is acquired by using an I&C (Incremental Conductance) technique. In IM, a voltage control scheme is utilized, which controls the frequency and voltage at point of common coupling (PCC). The efficacy of cascaded SOGI based technique is demonstrated through test results at various conditions such as vaying load, changing solar irradiance and transition between the modes of operation.

Battery-based electric spring has a great potential of providing various ancillary services in distribution systems. However, by far, a half-bridge inverter has been mostly employed as a single-phase electric spring. Thus, in this work, a seven-level electric spring with superior efficiency and power quality performance using modified seven-level pack U-cell inverter suitable for both low and medium voltage applications has been introduced. The operation principles, topology, comparison with the conventional electric spring configuration, and sensorless seven-level pulse width modulation method of the introduced seven-level electric spring has been presented. Furthermore, an RCD based control method has been utilized for the seven-level smart load setup for the first time. Finally, extensive simulation results have verified operating characteristics and performance of the proposed multilevel electric-spring-based smart load for both stabilizing the point of common coupling voltage and improving the power factor of the noncritical load during various steady-state/transient conditions.

This paper proposes a control strategy for a nine-level Packed E-Cell (PEC9) converter to act as Static Synchronous Compensators (STATCOMs). The controller is aimed to support grid stability through controlling the injection of PEC9 active and reactive power. The controller is designed in such way which second-order responses for the errors of PEC9 power can be reached. By analyzing the responses, a tuning process is presented for the controller coefficients as well. Simulation results in MATLAB/SIMULINK verifies the ability of proposed PEC9-based STATCOM.

This paper presents a single-phase neutral point clamped (NPC) multilevel converter (MLC) configuration for grid-connected photovoltaic (PV) applications. A single-stage control is implemented to feed PV array power to the grid at unity power factor. The direct and quadrature components-based controller is designed to have independent control on active and reactive powers injection. A low computational DC component injection based neutral point voltage (NPV) balance regulator ensures equal charging and discharging of DC-link capacitors. Moreover, the pulse width modulation technique with unipolar pattern is applied at lower switching frequency to adhere with minimum switching losses and power quality standards. The system performance in terms of parameters such as NPV balancing, converter voltage harmonics, the grid current harmonics, and unity power factor operation is analysed at variable irradiances. Simulation results are obtained using MATLAB/Simulink are validated using OPALRT test bench.

Electric vehicle (EV) charging station integrated into the photovoltaic-based microgrid (MG) is emerging as a promising alternative energy storage solution for MG connected to the low-voltage distribution network. However, the lack of commitment from EV owners to share their vehicle storage capability while parking, challenges to ensure the economic operation of the system. In this paper, we propose a dynamic pricing scheme that is constructed by varying charging price and vehicle-to-grid rewards to encourage the participation of EV battery reserve to minimize operating costs for the MG and de-stress the distribution network while satisfying all physical and operating constraints. A PSO technique is applied to search for the optimal dynamic price and reward, then the model is reformulated as a MILP problem. The numerical simulations investigate three different scenarios of the arrival/departure period of the EV fleets to demonstrate the effective impacts of integrating EV into the PV-based MG and distribution network. Furthermore, the proposed method outperforms when scheduling the dynamic pricing and optimal energy trajectory for 24 hours ahead with the 1-hour interval.

Multilevel inverters provide various advantages over conventional inverters. However, control and switching these types of inverters is a challenge for an increased number of levels that necessitate a higher number of semiconductor devices. Space Vector Modulation (SVM) switching method is a popular one that provides several advantages over conventional Sinusoidal Pulse Width Modulation techniques. Advantages such as higher output voltage, lower switching loss, lower dv/dt, etc. Despite its advantages, the SVM switching method requires complex time-interval equations. This complexity increases exponentially by increasing the number of levels. In this paper, a new SVM method based on Deep Reinforcement Learning (DRL) is proposed. The latter is based on a Reinforcement Learning Agent (RL-Agent) that tries all the "allowed" switching states of an inverter regarding the reference signal in each time step. Then based on the accuracy of the output, the agent receives a reward or punishment (negative reward). Over several episodes of trial and error, the agent learns how to perform the switching to receive the maximum long-term reward. Since the agent is also rewarded for keeping the voltage of the DC-link capacitors in a given range, this method is capable of voltage balancing. This method is implemented on a three-phase three-level Neutral Point Clamped (NPC) inverter for performance evaluation. The RL-agent is trained in MATLAB while the inverter model is simulated in the Simulink environment. The simulation results demonstrate the decent performance of this method.

Power electronic converters are the crucial components of numerous applications. Due to the switching nature of power electronic converters, they behave nonlinearly. Thus the detailed modeling of such converters imposes a huge complexity and calculation burden on their simulation. This complexity grows exponentially when the detailed models are integrated into the simulation of large networks. In this paper, a large signal modeling technique based on long-short term memory networks is proposed. The black-box approach enables the method to model commercial over the shelf converters. The size of the network provides enough degree of freedom for tuning a trade-off between complexity and accuracy. A DC/DC buck converter is modeled using this technique to validate its performance. The training datasets are obtained from the MATLAB/Simulink switching model of the converter. A long-short term memory network (LSTM) is then trained using MATLAB's deep learning toolbox. The obtained results demonstrate the performance of the proposed method over conventional black box modeling techniques based on neural networks.

Compact Multilevel Converters (CMCs) are type of converter topology where both DC sources and AC loads are clamped by active switches and the load current directly passes though DC sources. The H-bridge has been emerged as the first generation of CMCs, but later H-bridge has been developed as Packed U-Cell (PUC) using auxiliary DC capacitors instead of extra DC sources and optimizing number of components. Recently, an advanced CMC based on the PUC has been introduced so-called as Packed E-Cell (PEC) which is further optimized compared to PUC topology. The main challenge in CMCs including PEC is to balance the auxiliary DC capacitors in a low switching frequency technique. In this paper, DC capacitor voltage balancing of PEC is investigated at a low switching frequency operation using Selective Harmonic Mitigation (SHM) modulation technique. Some theoretical and simulation analyses have been performed to evaluate the performance of PEC under low switching frequency operation.

This paper proposed a PI based control technique for grid-tied application of recent introduced compact multilevel inverter so called as Packed E-Cell. The nine-level Packed E-Cell (PEC9) benefits the advantage of single auxiliary and main dc source where the dc capacitors are placed in a horizontal extension on the single auxiliary dc link where simultaneous charging and discharging with effective redundant switching states are provided. Therefore, PEC9 is an active capacitor voltage-balancing converter where the capacitors voltages are adjusted to the right amplitude using only redundant switching states. Thanks to this prominent advantage, PEC9 is an appropriate nine-level topology for grid-tied inverter as the capacitors voltages are not required to be involved in grid-tied control technique. Therefore, it was shown that PEC9 inverter can be perfectly controlled with a simple PI technique for grid-tied configuration. The proposed PI-based technique has been tested using Matlab-Simulink on grid-tied PEC9 inverter under both steady-state and dynamical operation.

The advantages of modular multilevel converters (MMC) over conventional two-level converters have lead to new emerging topologies and applications. The MMC with series/parallel connectivity (MMSPC) is one of the more recent topologies that can provide stable and efficient sensorless operation by introducing an additional parallel connection state between modules. However, while the parallel functionality has great potential in simplifying control and monitoring, it complicates the analysis of the system. The equivalent resistance of the MMC can be helpful in analyzing the conduction losses and also in designing appropriate heat management systems. Estimating the equivalent resistance of an MMC structure with half-bridge submodules is a straightforward procedure. However, performing a similar analysis for MMSPCs is more difficult, mainly because of the parallel state. In this paper, a simplified semi-analytical equivalent-resistance analysis method for MMSPC with full-bridge submodules (SM) is presented that can increase the speed of analyzing the system. Furthermore, the derived equations are compared to MMC with half-bridge SMs to provide better insight into the effect of varying parameters of the system.

Pulse width modulation converters are increasingly used to connecting to the power grid. This paper presents an enhanced systematic comparative analytic approach for the indirect matrix converters that are actively modulated by two frames: DSVPWM & Hybrid SPWM. Details of proposed mathematical models, simulations & graphical qualifications are presented & discussed.

Inductive Power Transfer (IPT) in EV chargers enables range extension opportunity by rapid in-station or dynamic charging of batteries. Enhancement of transferring power and distance ranges and improvement of mutual coupling between coils have always been in the two opposite sides of every wireless power transfer system. A trade-off between transfer efficiency, distance, and power is essential for electrical vehicle applications. Despite previous researches on electromagnetic modeling of IPT systems, it still suffers from noticeable lack of models which shows mutual inductance between the primary and secondary coils and losses in the coils. This paper presents analytical methods to study mutual coupling between coils and considers effects of misalignment on them. A detailed analytical investigation of a pitch rotation misalignment about the y-axis and a lateral translation misalignments in the y-axis direction is presented for a commonly used topology, circular coils, among existing ones applicable to IPT EV chargers. The analytical methodologies have been also evaluated by means of numerical method.

The integration of renewable energies as dc power sources is increasing in dc micro-grid that is gaining more importance than ac micro-grid because it requires fewer conversion stages. Also electrification through electric vehicles (EV) is encouraged due to their reduced fuel usage and greenhouse emission. In this paper, the integration of solar energy through photovoltaic panels (PV) in dc micro-grids as an assisted approach for EV charging is presented. EV has the ability to operate as electric source or load. In Vehicle to grid technology (V2G), EV can transfer the energy stored in its battery back to the Grid.

In this paper, an improved Adaptive Neural Fuzzy Inference System (ANFIS) based controller has been designed to regulate the capacitor voltage and load current of Seven-Level Packed U-Cell (PUC7) inverter. PUC7 is an affordable topology due to the least power switches and DC sources; but, it suffers from unstable adjusting capacitor voltage level. Proportional Integral (PI) as a simple linear control method causes overshoots and undershoots in transient response and conducts the system to unstable mode when some uncertainties are existed in the load. However, the proposed ANFIS control method regulates the load current and balances the capacitor voltage without any overshoot or undershoot and transient response even in presence of nonlinear loads. Simulation results of stand-alone mode of operation of PUC7 obtained by MATLAB software also confirm usability of ANFIS control loop to achieve unity power factor, minimum Total Harmonic Distortion (THD) and minimum capacitor voltage ripple while the PUC7 inverter is connected to an AC dynamic load.

A new nine level inverter is presented in this paper. It combines PUC and NPC topologies to create a new competitive converter that makes use of small count of power devices to generate more voltage levels. A PWM technique is designed to insure the self balancing of capacitors voltages. Moreover, no filters or regulation loop is required which permits a low inverter and installation cost. Authors make use of Matlab Simulink environment to perform the simulation of the proposed concept. Dynamics of the latter was verified against load and DC source voltage change.

In this paper, the method to extend linear modulation range till full base speed irrespective of the load power factor (p.f.) is presented using a 5-Level inverter scheme. Using this method, inverter can be operated linearly till peak phase fundamental voltage of 0.637Vdc(i.e. till full base speed) without exceeding machine phase voltage rating. The 5-level inverter is realized by a dual-fed inverter scheme for Open-End Induction Motor (OEIM) drive. A 2-Level inverter cascaded with a H-Bridge inverter acts as primary inverter and feeds the drive from one end whereas capacitor fed 2-Level inverter acts as secondary inverter and feeds the drive from another end. A single DC source is connected with primary 2-Level inverter. The ratio of the DC-link voltage to the primary H- Bridge inverter capacitor voltage is 4:1 and the DC-link to the secondary inverter capacitor voltage is maintained at 2:1 ratio for proper 5-Level inverter operation. Simulation and experimental results for inverter operation till full base speed are presented in this paper for OEIM and resistive load under steady state and dynamic conditions.

In this paper a fixed-switching frequency Pulse width modulator (PWM) based-Sliding Mode Control (SMC) is proposed and applied to a single phase/Five-Level/Sensor-less Packed U-Cell (PUC5) interfacing the utility. The new design takes the advantage of chattering compensation when Gao's reaching law is adopted. SMC-based controller takes in action of maintaining the utility current at a desired reference value with unity power factor and fixed-switching frequency operation. Due to self-voltage balancing feature of PUC5 inverter, auxiliary DC capacitor voltage is regulated through redundant switching states while no sensor, neither regulator are needed. The overall SMC-PWM proposed controller is less complex, more robust towards external disturbances making it suitable for single-phase renewable energy systems interfacing the utility. Simulation results on MATLAB/Simulink are provided to confirm the effectiveness and robustness of the proposed controller.

This paper presents a control strategy for a Multi-Terminal MMC-HVDC system to enhance the frequency response of AC grids. Using power sharing of both upper and lower arms of MMC combined with a basic equation of control functions, the proposed upper and lower control functions are extracted. In these proposed control functions, total wasted power in both upper and lower arms along with the power generated by the arm inductances are considered. The proposed control functions are capable of providing accurate performance with fast frequency response for AC grids with the existence of both load variations and DC voltage fluctuations. MATLAB/SIMULINK software is employed to demonstrate the merit of proposed controller.

This paper proposes a novel sensor-less switching method based on logic gates for a five-level packed U-cell (PUC5) converter. It comprises only two level-shifted triangular carriers and logic gates. Hence, the number of triangular carriers is halved and the switching states table is eliminated, which cause remarkable reduction in complexity of the proposed modulation method. Moreover, employing the proposed sensor-less switching method leads to decrease in the PUC5 capacitor value by a factor of carrier ratio, fast self-balancing of the PUC5 capacitor voltage, and halving the output LC filter inductor and capacitor values in stand-alone mode, as well as the grid-link inductor value in grid-connected mode. In addition, the PUC5 converter start-up transient time is considerably decreased and the first switching harmonic cluster frequency is doubled, which lead to notable improvement of steady-state and dynamic performances of the PUC5 converter. The proposed sensor-less switching method has been implemented in both stand-alone and grid-connected operating modes of PUC5 converter. Provided simulation and experimental results verify the feasibility and effectiveness of the proposed sensor-less switching method as well as its improved dynamic and steady-state performances in both stand-alone and grid-connected modes.

This paper proposes a single switch open-circuit fault diagnosis approach for three-phase three-level NPC inverter based on conducted emissions. The proposed approach uses a simple electromagnetic interference (EMI) filter, placed between the DC source and the conversion system, to meter conducted interferences. A time-domain analysis of the voltages across the EMI filter resistors is, firstly, utilized to identify the two pair semiconductors among the two upper or the two lower switches. The Teager energy operator based algorithm is, then, applied. This latter proves the efficiency of this method for the identification of the faulty switch. The effectiveness of this pioneering approach is enhanced by simulation results.

In this paper, a deadbeat predictive direct power controller (DPC) is proposed for neutral-point-clamped (NPC) converter based active front end (AFE) rectifier for more electric aircraft (MEA) applications. In the proposed AFE rectifier, the input filter inductance value and size are remarkably reduced by employing 3L-NPC converter, which leads to notable increase the power density of the attained AFE rectifier. Moreover, the novel deadbeat predictive DPC is proposed to achieve constant switching frequency, continuous sinusoidal input current, unity PF as well as fast transient response in presence of wide frequency variation of AC power supply source. The performance and feasibility of the proposed deadbeat DPC for 3L-NPC based AFE rectifier are verified by the simulation results.

In this paper, a novel sensor-less logic-equation-based modulation method for grid-connected PUC5 converter has been proposed. It consists of only two triangular carriers and logic equations, in which the number of triangular carriers is halved and the switching states table is eliminated. Hence, the complexity of the proposed modulation method is remarkably reduced. Moreover, by employing the proposed modulation method, the capacitor value of PUC5 converter is decreased by factor of carrier ratio, faster self-balancing of capacitor is achieved, and the PUC5 converter start-up transient time is considerably decreased. In addition, first switching harmonic cluster frequency is doubled, which leads to halving the grid link inductor size. Hence, notable improvement of steady-state and dynamic performance of grid-connected PUC5 converter is obtained. The provided simulation results confirms the performance and feasibility of the proposed sensor-less logic-equation-based switching method for grid-connected PUC5 converter.

This paper presents and discusses the viability of 3-phase hybrid series power filter compensator in a realistic distribution network. The proposed configuration can challenge unified power quality conditioner (UPQC) with less components and a cost. It ensures power quality by compensating current harmonics, reactive power, sag voltage, swell voltage and unbalance voltage. The main contribution is the proposed configuration integrating a control algorithm of the series active filter to compensate reactive power rather than using a thyristor controlled reactor (TCR). The strategy consists of integration a current source angle in the reference voltage to shifts a reference voltage to get unity power factor in the grid side. The sliding mode control (SMC) which a powerful control ensures a stability using Lyapunov candidate function validation. In order to reduce the rating of the active filter, a design of the passive filter is integrated to take care of reactive power and current harmonic compensation due to its low impedance at the harmonic frequency. The studies include simulation results and evaluations of the passive components used to compensate current harmonics. For the validation, an implementation and testing results are carry out using Matlab/Power Systems (PS).

The paper proposes a novel integrity of both a topological aspect characterized by the indirect matrix converter, and a modulation aspect characterized by the pulse width technique. This integrity brings to completion an entire akin grid-tie topology implemented using digital signal processing operation. The latter gives birth to a solid competent solution in terms of system performance, quality of signals, computation time reduction, & unity power factor feature.

In this paper, a new hybrid charging algorithm suitable for Li-ion battery is proposed with the aim of reducing refilling time and improving battery life cycle. The hybrid algorithm combines constant current constant voltage (CCCV) and pulsed charge (PC) techniques to obtain the suitable way for fast charging and ensure a long lifetime. A step by step execution of the new algorithm is presented. Moreover, the algorithm is implemented using bidirectional DC to DC power converter with Simulink. The charger is able to detect initial battery state of charge (SoC) and take the suitable way to charge it. The included results show the obtained performance of the proposed technique in terms of battery refilling time reduction to return to top of-charge and improving its cycle life.

This paper presents the design of space vector modulation (SVM) technique to control the switches of single phase sensor-less 5-level Packed U-Cell inverter (PUC5) along with voltage balancing at flying capacitor. To generate five equal voltage levels at the output waveform, which results in reducing total harmonic distortion (THD) the switches of PUC5 should be properly triggered. Utilizing SVM technique by tuning the interval time among the state vectors on PUC5 inverter is discussed at this paper for voltage balancing at auxiliary capacitor. Moreover, appropriate patterns of switching states are used in this paper to reduce the switching losses by minimizing the transition from one state to another state. Simulation results by MATLAB Simulink are presented to validate the capability of proposed modulation technique. Furthermore, a comparison between the results of level shift pulsed width modulation technique (LS-PWM) and SVM is carried out to demonstrate the lower power loss of SVM.

This paper presents a robust fuzzy-based control strategy for single-phase five-level PUC5 inverter in grid-connected mode that can properly improve the grid power quality. The proposed control technique is able to provide unity power factor between grid voltage and current by accurately injecting the needed load currents in presence of unmolded uncertainties. To provide robust property, the proposed fuzzy-based control strategy for accurate operation of PUC5 in grid-connected conditions has been designed. Simulation results in MATLAB software verify the proposed control technique abilities at achieving very low THD grid current, unity power factor, appropriate output voltage and SPWM reference signal.

This article presents a new method for controlling the output voltage of the voltage source inverter (VSI) for stand-alone systems using finite control set model predictive control (FCS- MPC). In the existing conventional method, such as sinusoidal pulse width modulation (SPWM), the output voltage is varied by varying the amplitude modulation ratio (ma), which can be problematic if the value of (ma) exceeds 1. The conventional SPWM method also suffers from slow transient response. To solve the aforementioned problems, FCS-MPC is proposed for stand-alone VSI. The proposed method precisely controls the output voltage by varying the weighting factor of the cost function in the FCS-MPC algorithm. The proposed technique enhances the transient response, improves the THD and provide stability under all tested conditions. Based on the single step prediction set, it has a low computational load with improved performance. The feasibility of the proposed method is verified by simulations in MATLAB/Simulink.

A three-phase Transformerless hybrid power filter (THSeAF) based on a seven-level Packed U-Cell converter (PUC) to correct major power quality issues related to the more electric aircrafts (MEA) is proposed in this research work. This power quality compensator presents an affordable solution to overcome current related issues as well as ensuring a viable supply to the onboard loads. The PUC converter combines advantages of the flying capacitor and the cascaded H-bridge topologies. This solution is promoting Active power filtering application for higher voltage level with smaller passive component ratings. Based on the Synchronous Reference Frame (SRF) along with the use of the p-q theory, the controller extracts the voltage and current distortions and voltage unbalances. Then, a proportional plus resonant (P+R) controller is producing the gate signals for all three-phase IGBTs. To rectify harmonic currents produced by typical distorted loads, the duty-cycle waveform should produce the according voltage waveform. Beside the proposed technic to improve power system performances on the MEA, this article proposes a universal solution to enhance the power quality problems found in a micro-system and/or distribution level system. Simulation results illustrate the performances of the proposed configuration.

In this research paper, the authors propose single-phase Transformerless Hybrid Series Active Filter called a THSeAF based on a seven-level Packed U-Cell converter (PUC) to address power quality issues related to distribution systems. The PUC converter has both advantages of flying wheel capacitor and the cascaded H-bridge topologies. This solutions is promoting Active power filtering application for higher voltage level with smaller passive component ratings seems a durable solution to overcome current related issues as well as integration of renewable sources for sustainable supply. The main significant features of the proposed configuration is the great competency for correcting the sags and swells as well as the power factor and cleaning the grid, while protecting consumers from voltage disturbances, during a grid perturbation. This paper is trying to investigate aspects of harmonic compensation and assesses the influence of the PR controller's choice and time delay for a realtime implementation. A combination of simulations and analysis are made on a typical study case to illustrate the efficiency of the proposed configuration.

A control technique based on dynamic model of stand-alone single-phase voltage-source converter (SPVSC) in dq reference frame and droop curve equation is proposed in this paper to stable the voltage of point of common coupling (PCC) when renewable energy resources (RERs) are linked in a microgrid structure. The proposed control strategy is designed with respect to the aimed state variables of PCC frequency and voltage magnitude as well as the droop curve specifications. Moreover, an evaluation on PCC voltage frequency and voltage magnitude-based curve is presented for further analyzing the proposed controller performance. Simulation results in MATLAB/SIMULINK software prove the abilities of proposed controller in reaching stable operation of PCC voltage in microgrid application under load alteration.

This paper presents an insight into a digital twin concept based on finite element simulator of a large hydro generator. The digital twin is created using finite element technique to design, study, monitor and to perform tests including analysis of a large hydro generator operating in normal and both margins of the capability curve. A three-phase synchronous machine generator of 310MVA, 56 poles, 13.8kV was considered for the case study. The created model was validated according to the IEEE standard 115. The presented and discussed results are related to the air gap magnetic flux density distribution and damper bar currents for operation in both under and over excitation modes.

In this paper, authors propose a hysteresis controller insuring the self balancing of the capacitors voltages without using any voltage sensor. Capacitors voltages of the fifteen-level PUC inverter have to be maintained around their references using a state variable feedback which requires three sensors, two for the capacitors voltages and one for the load current. The proposed nine-level inverter associated to the proposed control technique allows, in open loop operation, a self balancing of the capacitors voltages. The proposed balancing technique is achieved without any voltage sensor or voltage closed loop. The proposed concept has been verified by mean of simulations performed in the Matlab Simulink environments. Simulation results show that even under severe load parameters variations, the capacitors voltages remains around their required values. Harmonics distortion of load current depends on the hysteresis bandwidth.

This paper investigates Power-quality improvement of the traction power-supply system (TPSS) of the trains. The integration of renewable energy and distributed generation to railway trains supply systems combined to the power quality constitutes technically a major contribution in the paper. The present work deals with the design and control of PV solar and two single-phase five level inverters associated with LeBlanc transformer to supply two single phases' loads and generate a 750 V for utilities for the train. The supply of railway system from three-phase grid to two phases constitutes a challenge when the loads in the train side are unbalanced. The proposed configuration ensures complete compensation of unbalanced loads, the reactive power, and the current harmonics in three phase grid system. The control of both inverters uses a sliding mode and an indirect control respectively. The first inverter control regulates the dc bus voltage, compensates the reactive and the current harmonics for the correspondent phase. The second indirect control applied to the second inverter compensates the reactive, the unbalance secondary current and the current harmonics for the correspondent phase. The current balance between the two single-phase sources ensures a balance of three phase's current in the grid side. The proposed system is modeled; simulated using Matlab Simulink/Power Systems and the performance of the proposed system is analyzed and discussed.

This paper presents three approaches, the first to upgrade the droop control to improve the performances when paralleling five inverters connected to the PV solar. The second compares the two approach connections of PV solar using two methods, the series parallel (SP) and the Total Cross Tied (TCT). The third proposes the MPPT algorithm for power maximization of the PV solar during shadow problem. The proposed droop control generates references for nonlinear control to regulate the state variables of the inverters, their output voltages to reduce current circulation between the inverters, the dc bus voltage and the current harmonics. The master inverter regulates the total reactive power in the source side in order to obtain unity power factor. The others inverters (slaves) regulate their respective output voltages to track the master inverter voltage. The control approach proposed is dedicated for equal or different power ratings of any number of parallel inverters with different PV solar power operation. For far inverters station distance, wireless communication may be used from the master to other slave inverters. Many tests are validated by varying the PV power and the load of the proposed control approach.

Multilevel inverters (MLIs) are known as one of the most widely used power converters in power electronic fields. This study proposes a new voltage source inverter (VSI) for MLI with reduced number of components. The recommended MLI is implemented with 8 DC links and 18 switches, which generates 33 output voltage levels in asymmetric source configuration. All voltage levels (positive, negative and zero) are synthesized at the output terminals without any additional circuit. Cascaded connection of the topology is also proposed. Compared with other conventional and recently invented topologies, it uses less number of components. The accuracy performance of the suggested MLI in synthesizing the positive, negative and also zero voltage levels is verified over the simulation results (MATLAB/SIMULINK software) on a 33-level inverter.

This paper proposes a control algorithm that controls a DC/DC converter within a capacitorless battery charger for Electric Vehicles (EVs). The charger is composed of an AC/DC converter connected to a three-phase DAB (Dual Active Bridge) DC/DC converter with no capacitor between those two. The proposed control adds an additional degree of liberty in order to deliver the reference charging or discharging power while mitigating the DC/DC converter's drawbacks, dealing with a varying voltage since there is no capacitor, operating in a wide range power spectrum, and controlling the transitional instants. The control algorithm's performance is verified using Matlab/Simulink, and the results are discussed.

This paper presents a concise review of the novel matrix converter technology widely recognized in the last two decades attracting all scientific institutions, industrial markets, and governmental foundations towards developing it. The appealing features of the topology along with its structural characteristics are clearly highlighted. A state-of-art demonstration of the highly adopted modulation techniques is presented. Brief clarifications covering converters' efficiency and losses, protection issues including input filters are shown.

The paper proposes a hybrid modulation algorithm that combines the space vector modulation technique (SVPWM) to control the rectifier stage and a new digital scalar modulation method (DSPWM) applied to the inverter stage. Compared to the conventional SVPWM method, the proposed DSPWM technique of the inverter stage is easier to understand and to be implemented. DSPWM allows reducing real-time computation difficulties under high quality preservation of grid and load currents' performance.

This paper proposes a dual output Luo converter fed SRM (Switched Reluctance Motor) drive. The proposed converter generates two symmetrical output voltages. In order to obtain PFC (power factor correction) operation drive is operated in DCM (discontinuous conduction mode). The current through two output inductor is discontinuous in each switching period. The converter provides high efficiency, high power density and simple structure. The regulated output voltages of proposed converter are fed to SR motor. The SR motor here is selected for the drive due to its low cost and easy construction. The variable speed operation of proposed drive is obtained by varying DC link voltage. The proposed converter configuration has controlled DC link voltage with power quality improvement at supply. Simulation results shows the PFC operation with reduced input current THD below 5%, as per the given IEEE standard.

Going forward to reach infrastructure grid by incorporating cluster of renewable and distributed energy sources, storage systems, different kinds of loads, in a huge dimension of information, communication and control technologies, has been established concept of “Smart Grid”. By jointly considering local distributed generation, i.e. two small wind turbines, PP load, i.e. fast charger of electrical vehicles (EVs) on a grid, and a set of linear and non-linear loads, in this paper, power quality features in a smart grid are analyzed comprehensively. The grid has been modeled in MATALB/Simulink. To validate, results are compared with EMTP results.

This paper investigates the effects of unintended island operation mode on parallel inverters' performance for microgrid applications. In the grid-connected mode, each inverter has a different power set point. The power flows between the inverters and the grid. In the islanding mode, the power flows inherently from the inverter that has higher set point power to the inverter has lower one leading to a substantial and rapid increase in dc-link voltage. Consequently, a controller is needed to protect the inverters from highly dc link voltage (HDLV) that may lead to fatal damages of the capacitor and power switches. However, the use of a dc-link controller for the second inverter makes unstable the first inverter dc-link voltage regulation. This work proposes a fuzzy logic controller (FLC) designed to avoid any rising in DC link voltage DLV for the second inverter and make it more stable. The effectiveness and performance of the proposed control method are demonstrated with numerical simulations carried out for three operation scenarios. The first one deal with two inverters operating in islanding mode where each inverter has a different set point P*1= 20 kW, and P*2= 0 kW. The second scenario considers two inverters operating in grid connected mode before being switched to the unintended islanding mode at a specific time without using dc-link voltage controller. And finally the third scenario investigates the effect of adding a dc-link voltage controller (DLC) to the system.

This paper presents an approach for upgrading droop control aimed to improve its performance when used for two parallel inverters. The proposed control ensures equal voltage for the two inverters when different power flowing through them which guarantee zero current circulation. To fulfill the voltage regulation, the second inverter (slave) regulates its voltage to follow the master inverter reference by adding a drop voltage to the reference established by the droop control of the second inverter. The current harmonic compensation is also controlled by the slave inverter using a notch filter for harmonics and reactive current extraction. For the master inverter, a control algorithm is integrated to compensate the reactive power exchanged with the grid side in order to obtain the grid voltage in phase with the grid current. The control approach proposed may be used with equal or different power ratings of any number of parallel inverters, provided that the slave inverters should regulate their voltage according to the master reference inverter. For long distance inverters station, wireless communication may be used to transmit necessary information from the master to other slave inverters. The MSC (Master Slave Control) method is used and the first inverter specified as the master, and the second is the slave. Different tests are undertaken by online variation of the power and the inductor of the second inverter to validate the proposed control approach and robustness.

Transformerless photovoltaic (PV) inverters offer several advantages in terms of weight and cost reduction as well as a higher efficiency compared to the topologies with transformers. However, the removal of transformers results in the establishment of a direct connection between the PV panels and the electrical grid which, consequently, leads to the generation of a leakage current. This current is flowing from the ground to the PV array through the stray capacitors causing undesirable distortions in the grid's output current in addition to several losses in the power conversion system. The high frequency variation of the common mode voltage (CMV) represents the main cause of this current. To overcome this issue, three innovative Space Vector Modulation (SVPWM) techniques were recently developed for NPC inverters with the aim to stabilize the CMV. These techniques are namely Long Medium Zero Vectors Modulation LMZV, Three Medium Vectors Modulation 3MV, and, Two Medium One Zero Vectors Modulation 2MV1Z. This paper evaluates the performance of the aforementioned techniques through a comparative analysis based on numerical simulations carried out on a three-phase three-level NPC inverter.

The aim of this work is to realize a system which ensures the wireless power transfer to supply a load situated at a distance from the source. This system consists mainly of two circuits: one primary and other secondary. In its design one have used the Zero Voltage Switching (ZVS) technique in the primary circuit to improve the efficiency by reducing losses caused by MOSFET switches, and the resonant inductive coupling to ensure the energy transfer. This technique is classified as the most effective for these type of applications. Initially the system is powered by a 15V/3A DC voltage. Finally, the proposed system can feed a load located at a distance equal to 15 cm.

As HVDC based on voltage source converter (VSC) technology has already reached 350 kVdc voltage level, this paper examines the feasibility of connecting four voltage source converter (VSC) modules, each rated at 200 kVdc, in series to form a pole of UHVDC rated at 800 kVdc. Due to the series connection layouts, the individual DC bus voltage inequality exists when power reversal occurs. A detailed control solution with DC voltage compensation equalizer for the series connected VSC-UHVDC system is developed and presented. The operation feasibility of the proposed UHVDC system is verified via simulation studies under different conditions such as active power step changes, reactive power step changes, and power reversal.

This paper presents a smart DC network formed by a multi-terminal VSC-HVDC connecting various micro-grids, independent power generation stations, and passive loads. The corresponding deadbeat current control scheme based on coordinated strategy for multi-terminal VSC-HVDC systems is proposed. The current control scheme is easy to design, implement and has good dynamic response. the case of four-terminal VSC-HVDC interconnected with AC grids, wind farms, and passive loads is developed in MATLAB/Simulink to demonstrate the validity of the proposed control scheme and the united system. Simulation results have demonstrated that the proposed scheme enables optimal operation under conditions of voltage dip, power flow and load changes when used for a large DC smart network.

Modular multilevel converters (MMC) have been at the heart of numerous research projects and publications over the last decade. This topology is particularly challenging when it comes to real-time simulation; it has thousands of power-switching devices, control signals, and differential equations to solve. This has led to various models with different levels of detail. Although, all models are equally accurate, to some extent, it might not be required to use a fully detailed model depending on the objectives of the analysis. In this paper, five different MMC modelling techniques are studied for different number of submodules. Converter behaviour during initialization, normal operations and faulty conditions are investigated. The impact of the detail level of each model is reviewed for the different control loop of the converter, and also different faults applied to the converter.

A three phase to five phase configured twenty pulse AC-DC converter fed 3-level modular multilevel inverter (MMLI) based vector controlled induction motor drive (VCIMD) is presented in this work. To limit the total harmonic distortion (THD) in the utility current as per IEEE-519 standard, a twenty pulse AC-DC converter is used at the input end of the proposed drive. A three phase system is converted into two sets of five phase AC voltages to achieve twenty pulses in each cycle of the supply current. At the drive end, a 3-level MMLI is used to improve the steady state, dynamic and power quality performance of the drive. An indirect vector control with sinusoidal pulse width modulation (SPWM) is used to control an induction motor and 3-level MMLI, respectively. A twenty pulse AC-DC converter fed 3-level inverter based VCIMD is modelled and its performance is simulated in Simulink/MATLAB environment to demonstrate its effectiveness for medium power application.

This paper proposes two methods for optimal design of DC bus reference voltage (Vdcref) and an optimal selection of the shunt active filter (SAF) inductor. The proposed methods help to reduce the filter rating, devices stress and increase the performance of the SAF. An optimal choice of the inductor of the SAF is presented based on the slope calculation of the SAF current which was demonstrated to be greater than the slope of the nonlinear load current. Moreover, the adaptation of the DC reference voltage which is a function of the amplitude of total load current harmonics and load reactive current is developed and the latter offer important advantage in terms of losses reduction in the converter switches leading to a more accurate design of the SAF. To achieve these goals, the first developed method is based on the direct calculation of the maximum SAF voltage to determine the minimum DC bus voltage reference; while the second method is based on the estimation of the maximum voltage of the SAF through a control technique developed and applied to the model of the SAF. For validation purposes, the proposed methods were simulated. The simulation results validate the approach in terms of source current compensation, THD reduction, as well as the correction of power factor.

This paper presents a thorough study on Five-Level Packed U-Cell inverter called PUC5. The main advantage of PUC5 topology over other popular multilevel ones is the redundant switching states, which facilitate the voltage balancing of the flying capacitor in its configuration. Switching states of the PUC5 inverter are analyzed to ensure an easy voltage balancing process. That voltage controlled auxiliary capacitor helps generating five identical voltage levels at the output using a single DC source. A full comparison is done to other 5-level inverter topologies to reveal the dominant features of the PUC5 structure. Moreover, some discussion on the controller design for the PUC5 inverter is conducted in grid-connected applications which indicates similar procedure performed for conventional 2-level ones due to featuring single-dc-source configuration. Various experimental results are shown in each discussion for better understanding.

In this paper, a new 11-level topology of symmetrical Multilevel Inverters (MLIs) is proposed. The proposed topology offers reduced number of components as compared with conventional and recently published topologies. The Selective Harmonic Elimination (SHE) is adapted for switching modulation that removes undesired harmonics. A comparative analysis of proposed topology with other proposed topologies has been made in terms of number of switches, diodes, required driver circuit and DC voltage sources. The topology can be easily extended in three parts because of its modularity and extendibility to increase the output voltage levels. The feasibility of the proposed topology is verified by simulating the topology using MATLAB/Simulink, and also the high performance of the proposed topology has been validated experimentally.

This paper presents a new validation method to demonstrate the stability and accuracy of a discretized system by using multiple sampling rates. Such multirate simulations are often encountered in real-time simulation application, where large power systems are coupled with circuit containing power electronics devices. Multirate simulation should not be confused with variable-step simulation, which is a single-rate simulation type. In single-rate simulation, the discretized system is stable when its discrete poles are within the unitary circle. When using multirate solvers, state variables are discretized with different sampling rates and poles location analysis for the system's equations cannot be used. This paper introduces a formal mathematical analysis demonstrating stability of multirate real-time simulation. System state variables, regardless of their discretization time step, are found in a single matrix. Classical pole analyses are thereafter used to test stability with poles location analysis. The method is given in a generalized form, and can be applied to various multirate solvers. The proposed method was found accurate and reliable using numerical examples.

In this paper, a multifunctional three-phase grid-connected single-stage solar photovoltaic (SPV) system is presented using an intelligent adaptive control technique. The system configures a SPV array, VSC (Voltage Source Converter), interfacing inductors, ripple filter and three-phase grid connected nonlinear loads. The system is multifunctional as it provides functions of two different modes: 1) It acts as a SPV energy conversion system supplying active power to the loads and grid as well as a DSTATCOM (Distributed Static Compensator), and 2) It acts as a DSTATCOM alone, when SPV generation is unavailable and mitigates several power quality issues such as harmonics attenuation, voltage fluctuations and flickers, reactive power compensation, power factor correction (PFC) and load balancing. It uses a single-stage converter topology with variable step-size least mean fourth (VSS-LMF) derived adaptive control technique for VSC switching incorporating perturb and observe (P&O) method for MPPT (Maximum Power Point Tracking). The performance of the presented system is validated through experimental results obtained on the developed laboratory prototype.

This paper presents a switched reluctance motor (SRM) drive with power factor correction. Here SRM drive up to 1 kW rating fed with midpoint converter is considered. As per the requirement buck boost converter is modified to obtain two equal DC output voltages to feed mid-point converter. The speed control of proposed drive is obtained by regulated DC link voltage. Here a closed loop control based on voltage mode control is designed to obtain the reference DC link voltage. The high frequency inductors of buck boost converter are design to operate in discontinuous conduction mode, to reduce system size. The supply current THD (Total Harmonic Distortion) due to peaky nature of current in conventional configuration is brought down below 5% as per IEC 6100-3-2 standard.

Wireless power transmission (WPT) has caused a radical change in the medical field, especially for medical implants. In this paper, a review of wireless power transmission history is given, its basic principle and it's very important role to load various medical implants such as cardiac, visual, gastric and endoscopic implants. The basic design of the WPT for each implant was been presented. This paper also outlines the safety consideration for human exposure to electromagnetic field.

A cascaded H-bridge multilevel inverter offers important advantages over the conventional two-level topologies, though it necessitates isolated input dc sources. Even power distribution amongst these sources is an important control issue for an enhanced life-time of the overall system. In currently used control schemes, for `n' number of input sources and a fundamental period `T' for the output voltage, average power drawn from each source become equal after cyclic time spans of `n*T'. In this paper, a methodology is presented using which these spans are reduced to `T', irrespective of the number of input sources. In the proposed scheme, sine-triangle pulse-width-modulation (SPWM) technique has been espoused to obtain a `multilevel reference signal'. This signal is further manipulated, so as to impart flexibility for the selection of redundant states. Actual driving signals for the power switches are then derived from the manipulated multilevel reference signal, utilizing chosen states such that the respective average currents drawn from the input sources are repeatedly equalized within one power cycle of the output voltage. Such flexibility is not directly offered by the standard multilevel SPWM methods. Simulation and experimental results indicate that for two input sources and an output voltage of 50 Hz, the conventional `carrier rotation' scheme requires repeated time-spans of 0.04 sec for even power distribution whereas the proposed scheme requires only 0.02 sec. Thus, the proposed scheme leads to a better and effective utilization of sources, especially when the number of input sources is large.

This paper presents a solar energy processor based on Packed U-Cells inverter for grid applications. The proposed single phase multilevel inverter PUC allows the generation of 7-level output voltage. Two control techniques are used in this work. MPPT is applied on the PV in order to extract the maximum power, while the aim of MPC or the model predictive control is to balance three variables in the system; the grid current, the capacitor voltage in the PUC as well as the BOOST output voltage. The feasibility of the designed system is validated by simulation using Matlab-Simulink-SimPowerSystems.

Cascaded H-bridge MLI is an attractive solution for grid connected PV system. DC sources can be replaced by PV module/panel and due to the separated DC link feature and the voltage control becomes possible. Thus, individual maximum power point tracking (MPPT) control in each PV module can be achieved, and the total power extracted from PV panels will be maximized and hence the efficiency improves In this paper, a single phase cascaded H-bridge multilevel inverter topology is proposed for grid connected PV system. The proposed multilevel inverter configuration consists of PV modules, each is connected to one DC-DC flyback converter to achieve best MPPT as well as used for galvanic isolation in order to improve system efficiency. The DC-DC flyback converters are cascaded to amplify the DC voltage in order to be used for medium and high voltage systems and the result output voltage is used as an input to one H-bridge inverter. H-bridge inverters are then cascaded to generate multilevel output voltage. On the other hand, the operation of H-bridge MOSFETS is that the two upper MOSFETS are operating at line frequency while the two lower MOSFETS are operating at switching frequency. This will reduce switching losses and hence extra improving system efficiency can be achieved. Finally, the proposed configuration improves the system efficiency due to the multilevel inverter, obtain the best MPPT, achieve isolation at high frequency, eliminating the leakage current due to parasitic capacitances between PV module and ground, decupling the second harmonic voltage ripple and reducing the switching losses in the inverters.

This paper introduces a new control scheme based on a Finite Set-Model Predictive Control (FS-MPC) and aims of a fixed switching frequency operation. The proposed scheme allows of obtaining a voltage vector that is responsible of nullifying the cost function's derivative for its optimization. Moreover, a closed-loop space vector modulation (SVM) based on the proposed predictive control scheme is introduced for a three-level grid connected inverter. The proposed algorithm that injects a desired current to the grid is investigated through external perturbations such as change in the line current amplitude as well as DC voltage variation. Discrete-time system model was developed and simulated. Simulation results on MATLAB/Simulink are provided to verify the fast dynamic performance, and good voltage balancing of DC bus capacitors of the NPC inverter.

This paper presents three phase single stage single source SPV (Solar Photovoltaic) grid tied system using asymmetric cascaded 27-level converter operating at fundamental switching frequency using pulse width modulation (PWM) scheme. An application of the asymmetric cascaded 27-level converter in comparison to symmetric cascaded 27-level converter have advantages viz. higher voltage levels, less distortion, low switching losses, simplicity of operation at high power that leads to the improvement of power quality of the system proposed herein. A simple decoupled current controller with incremental conductance maximum power point tracking method is used to control the proposed system. The simulated results in MATLAB validate the system under varying conditions such as solar insolations level.

This paper deals with a two stage solar photovoltaic (SPV) fed speed sensorless vector controlled induction motor drive (IMD) for water pumping system which is superior to conventional controlled motor as it is cheaper and reliable. One common practice is to estimate the flux from the terminal voltages and currents. The performance of the drive depends on the accuracy of the flux estimator. Usually the efficiency of the induction motor drive (IMD) is high around the rated load and deteriorates at partial loading. However, the efficiency can be enhanced by operating the motor at optimum flux by controlling the flux component of current. In this paper, a minimization technique is proposed to minimize the total losses to operate the drive at maximum efficiency. A modified perturb and observe (P&O) algorithm is used to track maximum power from SPV array. The smooth starting of the motor is attained by vector control of an induction motor. The system performance is simulated in MATLAB/Simulink environment and the results are compared with the conventional vector controlled IMD.

The newly emerged packed U-cell (PUC5) inverter topology is investigated in this paper considering the design criteria, switching technique, voltage balancing of DC capacitor and switches voltages ratings. Afterwards, It is compared with other popular multilevel inverter topologies such as 3-level full-bridge (FB), 5-level cascaded H-bridge (CHB), neutral point clamped (NPC) and T3, in terms of components count, voltage balancing complexity, voltage rating, switching frequency, etc. in continue, the 3-phase configuration of the PUC5 inverter is presented and its proper application would be discussed. Some experimental results are shown to accredit the performance of the 3-phase PUC5 inverter in 3-wire and 4-wire systems to supply 1-phase and 3-phase AC loads.

Multilevel inverters are the new structures of power electronic circuits that are used in high voltage DC-AC conversion systems. These kinds of inverters create more output voltage levels in which reduce the harmonic components. In this paper, a new three source multilevel inverter is proposed that consists of eight switches in basic structure. Proposed topology is aimed in symmetrical and asymmetrical state that can produce 7 and 11 levels in symmetrical and asymmetrical case, respectively. Modularity and extendibility are two important features of the proposed structure, so that the output voltage levels can be increased significantly. The Selective Harmonic Elimination (SHE) is utilized for switching modulation that omits selected harmonics. A comparative study between proposed structure, conventional topologies and recent ones with due attention to number of components is established. The proposed structure is simulated in MATLAB/Simulink software and a prototype is implemented in laboratory to validate the operation of the converter. The simulation and experimental results verify the accurate and proper performance.

In this paper, a new mode of operation has been introduced for packed U-cell (PUC) inverter. A sensor-less voltage control based on redundant switching states is designed for the five-level packed U-cell (PUC5) inverter, which is integrated into switching process. The sensor-less voltage control is in charge of fixing the dc capacitor voltage at half of the dc source value results in generating symmetric five-level voltage waveform at the output with low harmonic distortion. The sensor-less voltage regulator reduces the complexity of the control system, which makes the proposed converter appealing for industrial applications. An external current controller has been applied for grid-connected application of the introduced sensor-less PUC5 to inject active and reactive power from inverter to the grid with arbitrary power factor, while the PUC auxiliary dc bus is regulated only by sensor-less controller combined with new switching pattern. Experimental results obtained in stand-alone and grid-connected operating modes of proposed PUC5 inverter prove the fast response and good dynamic performance of the designed sensor-less voltage control in balancing the dc capacitor voltage at desired level.

Presents corrections to various diagrams and figures in the paper, "Sensor-Less Five-Level Packed U-Cell (PUC5) Inverter Operating in Stand-Alone and Grid-Connected Modes," (Vahedi, H., et al), IEEE Trans. Ind. Informat., vol. 12, no. 1, pp. 361-370, 2016.

This paper proposes a Single Phase Multilevel Active Power Filter (SPMAPF) for harmonic elimination and reactive power compensation. An asymmetric neutral point clamped five level inverter is used as an active power filter to improve power quality at Point of Common Coupling (PCC). The control algorithm of the SPMAPF is based on Lyapunov candidate. An energy-based Lyapunov control strategy is developed and tested for the SPMAPF. This method determines the control law that makes the derivative of the Lyapunov function always negative for all values of the states. Simulation results that are obtained by using Simulink/Matlab environment are presented to confirm the good effectiveness of the proposed control technique.

In this paper, a new algorithm is presented for maximum power point tracking (MPPT) of solar PV array. This method first forecasts the maximum power point (MPP) by using tangents to the power-voltage curve at two end points of an interval and then iteratively converges to the MPP by evaluating whether the true MPP lies on the left or right side of the estimated MPP. The proposed algorithm has the advantage that MPPT is achieved within an almost fixed and small number of iterations irrespective of the power level. The working of the control approach is first demonstrated through MATLAB/Simulink simulation and simulated results are then verified experimentally by the hardware implementation of a standalone photo-voltaic (PV) system.

This paper investigates on a three-phase Transformerless Hybrid Series Active Filter (THSeAF) to address major power quality issues related to residential and commercial buildings and presents an affordable solution to overcome current related issues as well as integrating renewables to ensure a sustainable supply. The controller based on a novel combination of Synchronous Reference Frame (SRF) and p-q theory to extract voltage and current harmonics and unbalances is developed in the paper. To produce gate switching signals for the three-phase THSeAF a conventional Proportional-Integral controller (PI) is used to produce reference waveforms produced earlier to rectify harmonic currents initiated from typical nonlinear loads. The device ensures a reliable and dynamically restored power supply on the load's point of common coupling (PCC) by means of three auxiliary DC supplies. This paper describes mitigation of power quality related issues into a micro-grid system. Combination of simulation results and analysis are carried out on a typical study case.

In this paper, Selective Harmonic Mitigation (SHM) and Selective Harmonic Elimination (SHE) modulation techniques are combined to generate the appropriated firing pulses for a 4-leg 3-Level Neutral Point Clamped (NPC) inverter. SHM modulation technique is applied to the phase legs in order to get a desired modulation index (ma) and to mitigate the lower order odd non-triplen harmonics (5th, 7th, ...) while the fourth leg firing pulses are generated using SHE modulation technique to eliminate the major low order odd triplen harmonics (3rd, 9th, ...) completely. It is demonstrated that this hybrid modulation technique can reduce significantly a vast range of harmonic orders in the NPC inverter output voltage when compared with the results achieved when using only SHE modulation technique in the four legs of the inverter. To avoid the generation of odd non-triplen harmonics in the SHM phase legs that can not be eliminated with the fourth SHE leg, the Simulated Annealing (SA) heuristic algorithm used to find the SHM switching angles is tuned in order to provided suitable oddnon-triplen harmonics distortions which can be eliminated with SHE technique. Moreover, since in dynamical applications the modulation index has to be changing continuously, the SA algorithm has also been designed in order to provide a smooth switching angles set to avoid undesired transients harmonic contents.

In this paper a grid connected photovoltaic (PV) flyback inverter operating in discontinuous conduction mode (DCM) is used to test a hybrid maximum power point tracking (MPPT) method. Moreover, the design procedure of a flyback inverter is also presented as part of this paper. The proposed hybrid MPPT method is a combination of fractional short circuit current(FSCC) and hill climbing (Perturb and Observe P&O) method. The proposed MPPT use current limits to detect abrupt weather changes and hence swiftly tracks the maximum power point (MPP) under dynamic weather conditions. This MPPT method is tested using co-simulation between PSIM and Simulink, where the control algorithm is implemented in Simulink and the grid connected inverter is executed in PSIM. The results shows enhanced energy harvesting compared with P&O when subjected to uniform and dynamic weather conditions.

In this paper, a component efficient multilevel rectifier is modeled and controlled using Model Predictive Control (MPC) technique. The recently introduced Capacitor Tied Switches (CTS) converter structure features two distinct dc-load terminals which can operate at different voltage levels while experiencing high voltage levels at the ac-side terminals. The CTS converter structure inherits attractive features from the efficiency and power quality perspectives, with excellent topology performance which was validated through different simulation scenarios.

A single-dc-source 5-level cascaded H-bridge (CHB) inverter is studied in this paper. All possible switching sequences are analyzed and a sensor-less voltage balancing approach is proposed that regulates the second dc bus (capacitor) voltage at half of the first dc bus amplitude (isolated dc source). The output voltage levels include zero, capacitor voltage and the dc source amplitude. The simple sensor-less voltage balancing technique is integrated into switching method which makes it easy to implement using even cheap microcontrollers. Simulation results validate the good dynamic performance of the proposed sensor-less voltage controller in regulating the capacitor voltage at the desired level to generate 5-level asymmetric voltage waveform at the inverter output low harmonics contents.

Packed U-Cell (PUC) converter has been introduced as a 7-level converter in early 2008. Since then, different analysis and projects have been performed on, including various applications such as inverter and rectifier, linear and nonlinear voltage controllers. In this paper, authors try to do a detail review on this topology covering all aspects like topology design in single and three-phase, operation concepts, switching sequences for different multilevel voltage waveform generation, modelling and etc. It is shown that this topology can be comparable to popular multilevel converters (CHB and NPC) in terms of device counts and applications. Moreover, some performed and published works about the PUC are mentioned to show its different industrial applications and some other converter topologies derived based on the PUC. Experimental results are provided to show the good performance of PUC converter in several applications.

This paper presents a 7-level cascaded H-bridge (CHB) multilevel inverter using a single DC source. The second DC bus is a capacitor that its voltage is controlled by switching sequences. The capacitor voltage is regulated at half of the DC source amplitude to have seven voltage levels at the output. Seven voltage levels include each DC bus voltage, their sum and subtraction. Switching pattern is designed based on the redundant switching states and multicarrier level-shifted pulse width modulation (PWM) technique to help controlling the capacitor voltage at the desired level. Simulation results are presented to validate the effective voltage balancing procedure integrated into switching technique and consequently generating the 7-level voltage waveform at the output with low harmonic contents.

This paper presents real-time simulation results of a 512-level modular multilevel converter (MMC). Using off-the-shelf computers and FPGA boards, the converter, including the 6 valves, 6 arm inductors and the transformer, is simulated with a time-step of 450 ns. Such a small time-step is required to ensure high accuracy when applying gating signals but also when observing fault conditions. Simulation stability is demonstrated for normal and faulty operation modes.

Three-phase four-leg neutral point clamped (NPC) inverter is more suitable in dealing with all sort of the loads especially unbalanced/nonlinear due to harmonics issues. Most control strategies applied on four-leg NPC are classified as high switching frequency lead to high power losses and low efficiency. In this paper, selective harmonic elimination pulse width amplitude modulation (SHE-PWAM) technique has been implemented on a four-leg NPC inverter to reduce the switching frequency properly. In SHE-PWAM technique, the amplitude of input voltage is considered flexible in order to eliminate one more harmonic order without increasing switching frequency. The obtained switching angles of phase legs and amplitude of input voltage are used to eliminate the non-triplen harmonics (5th,...,23th) from the output voltage. On the other hand, switching angles calculated for the fourth leg are considered to eliminate the triplen harmonics (3th,...,21th) from phase voltage. The performance of proposed technique is verified by Matlab/SPS simulations.

A hybrid Maximum Power Point Tracking (MPPT) method without using an irradiance sensor is proposed in this paper. The hybrid MPPT method is a combination of conventional Perturb and Observe (P&O) and Fractional Short Circuit Current (FSCC) MPPT technique. The proposed hybrid MPPT decides intelligently about the initial operating point of P&O by using the FSCC MPPT method. This method requires no sensor for irradiation measurement because it detects intelligently about the change in irradiance. Therefore, under dynamic weather conditions the decision about measuring the initial operating point of P&O is intelligent. After finding the initial operating point the system shifts to the conventional P&O method and starts to perturb with a small perturbation size. The use of small perturbation steps enables the system to work with less power oscillations around the Maximum Power Point (MPP), while the use of FSCC helps in rapid tracking of MPP especially under the varying environmental conditions. Thus, the proposed method is fast in tracking the MPP with less power oscillations and hence better performance in terms of energy harvesting when compared with the conventional P&O technique. Impedance matching between solar panel and load is achieved using a DC-DC boost converter and the proposed method is simulated in MATLAB/SIMULINK environment. The system is simulated against the steady and dynamic weather conditions. The results shows that under steady weather condition the proposed method harvests 5% extra energy as compared with the conventional P&O. For dynamic weather conditions the proposed method harness an additional 3.5% energy when compared with the P&O method, which makes it very promising.

In this paper a novel model of the packed U-cell (PUC) inverter is derived considering the concept of single-phase multilevel converters. Based on the proposed model, a voltage balancing controller is designed to apply on the 7-level PUC inverter. The applied controller is in charge of fixing the capacitor voltage in PUC structure at a desired value to have the seven levels of the voltages at the output. The 7-level pulse width modulation (PWM) technique is used to produce the associated pulses for firing the PUC switches. The performance of the introduced controller is investigated via simulations in various conditions including changes in the load and DC bus voltage variations. The results prove the ability of the good dynamic performance and fast response of the controller in stable and unstable conditions.

In this paper, different Distribution Static Compensators (DSTATCOMs) topologies, state of the art, their performance, design considerations, future developments, and potential applications are investigated for power quality improvement. These DSTATCOMs for three-phase three-wire systems and three-phase four-wire systems are developed and installed in the distribution system for many functions, such as reactive power compensation, harmonics elimination, load balancing, and neutral current compensation. This paper is aimed to explore a broad perspective on DSTATCOMs to researchers, engineers, and the community dealing with the power quality improvement. A classified list of some latest research publications is also provided for quick reference.

The predictions of the different magnetic core losses with acceptable accuracy are key parameters for temperature-rise calculations for any considered up-rate in large hydro electrical machines. In this paper, an overview of existing magnetic core loss models is reported. A new approach for the computation of the magnetic stator and rotor core loss is proposed. Finite element electromagnetic simulations were carried out on an existing hydro electrical generator rating 122.6 MVA, 13.8 kV, 60 Hz, 60 poles with 504 slots. The magnetic core losses were computed with the new proposed approach during the post processing in the stator and in the rotor. Finally, the obtained results are compared with other models and with the available test data.

This paper presents a review of the recent advances in matrix converter topologies used with the permanent magnet synchronous generator (PMSG) in wind power generation systems. Dedicated literatures introduce different topologies inspired by the conventional matrix converter. Two-stage matrix converters known as sparse matrix converters are compared to the conventional matrix converter in terms of implementation complexity, cost, power rating and voltage ratio. Single-phase matrix converters topologies are implemented in high power wind applications in two different modular concepts: the reduced matrix concept for offshore wind farms and the multi-modular high power matrix converter. On the other hand, several modulation techniques applied to the matrix converter-PMSG scheme are briefly presented.

This paper deals with the design and control of a connected wind hybrid generation system employing a Doubly Fed Induction Generator (DFIG) drove by a variable speed wind turbine and a variable irradiation PV solar feeding a three-phase four wire local loads. The ac terminals of the rotor-side converter are connected to the DFIG's rotor. A Maximum Power Point Tracking (MPPT) based rotor speed control is proposed. The PV solar is connected to the rotor-side converter. A nonlinear control is applied to grid-side converter, which operates as a shunt active power filter for compensating harmonics, unbalanced load currents and voltage regulation at the Point of Common Coupling (PCC). A new approach is also proposed for modeling the Voltage Source Converter (VSC). The proposed system is modeled and simulated using Power System Blockset Toolbox PSB of Matlab. The performance of the wind-PV solar hybrid system is presented to demonstrate its capability of MPPT, harmonics compensation, load balancing, and ac voltage regulation.

This paper presents a practical design and implementation of a modified Sheppard-Taylor-based Power Factor Correction (PFC) circuit used for single-phase low-voltage high-current applications. The proposed converter operates in Continuous Inductor Current Mode and Discontinuous Capacitor Voltage Mode (CICM/DCVM). In this mode of operation, the PFC provides zero-voltage turn-off switching, as well as natural input power factor correction over a wide range of input voltage. Due to the simplified control circuit and reduced switch current stress that it yields, this mode of operation offers better efficiency and higher reliability than the CICM/CCVM previously reported in the literature. The performance of the proposed PFC is analyzed through experimental measurements carried out on a 500W laboratory prototype. It is shown that this rectifier exhibits high input power factor and low line current distortion at very low output voltage level.

Due to recent energetic crisis, multilevel converters have been deeply studied to fulfill the growing demand with a high energetic efficiency. In this paper, authors propose a six-band hysteresis technique to control the novel seven level PUC-NPC converter. This converter combines advantages of the Packed U Cells (PUC) and the Neutral Point Clamped (NPC) topologies. A technique which allows a good system behavior and a low total harmonic distortion (THD) is proposed. In case of rectifier operation, the proposed six-band controller is designed to draw a sinusoidal line current (load current in case of inverter operation) with a unity power factor. Harmonics contents of line current (or load current) and rectifier input voltage (or inverter output voltage) are then very reduced which permits the reduction of the rating of active and passive filters resulting on a very high energetic efficiency and a reduced installation cost.

In various practical applications such as harmonic current elimination, reactive power compensation and power factor correction many adaptive filtering techniques are used for control of DSTATCOM (Distribution Static Compensator). This paper presents a comparative study of the performance of two weight updating adaptive algorithm LMS (Least Mean Square) based ADALINE (Adaptive Linear Neural Network) and Fuzzy logic based variable step size LMS used for harmonic current detection using VSC (Voltage Source Converter) based DSTATCOM (Distribution Static Compensator). Simulation results in MATLAB environment show that the convergence speed of fuzzy logic based variable step size LMS is much faster and its performance is better than LMS based Adaline under varying load conditions in DSTATCOM application for power quality improvement.

Renewable energy resources are widely used because of providing green and economic energy for the consumers. Multilevel inverters generates low harmonic waveforms at the output, therefore they are most suitable for energy conversion to deliver efficient power to the loads from renewable energy sources like photovoltaic systems. In this paper a new dc source less topology has been introduced for multilevel inverters. It uses crossover switches to generate the maximum output voltage levels. The Crossover Switches Cell (CSC) multilevel inverter can generate all possible voltage level among the DC supply and regulated DC voltage capacitor. A voltage controller has been proposed to keep the DC capacitor voltage regulated in case of load changes. The simulation results prove the capability of CSC in producing maximum voltage levels as well as the controller ability in balancing the capacitor voltage even if the DC supply voltage changes.

High power applications need high efficiency devices to produce lower power losses and harmonics while meeting the limitation of voltage and current. Multilevel inverters generate smoother and higher voltage at the output with lower harmonics. They can deliver high power while using medium-voltage switches. In this paper a Pinned Mid-Points (PMP) multilevel inverter topology is introduced and studied which is derived from a Bidirectional Neutral Point Clamped (BNPC) three-level inverter. The proposed PMP multilevel inverter has fewer switches and clamping diodes than the Cascaded H-bridge (CHB) and Neutral Point Clamped (NPC) inverters, moreover it has less bidirectional switches in comparison with the BNPC. Moreover, it can be extended to three-phase inverter same as a NPC only using three legs and common DC link. A five-level inverter using proposed topology is validated by Matlab/SimPowerSystems. It shows the appropriate results of voltage and current as well as their THD%.

This paper proposes a nonlinear derivative-less control approach for controlling a three-phase shunt hybrid power filter (SHPF). The dynamic model of the SHPF system is first elaborated in the stationary frame and then transformed into a “dq” reference frame. The control system is divided into two separate loops, namely the two current dynamics inner loop and the dc voltage dynamic outer loop. The exact feedback linearization technique is used to decouple the inner loop variables. Proportional-integral controllers are utilized to control the SHPF input currents and dc-bus voltage. The proposed nonlinear control is first simulated and then validated on a 2.5-kVA laboratory prototype supported by the DS 1104 digital real-time controller board of dSPACE. Satisfactory results, such as low-ac-current total harmonic distortion, fast step response, and high robustness under load variation, are obtained. Significantly high correlation between the experimental results and the theoretical model, implemented with SIMULINK/Matlab, is obtained.

This paper deals with the design and modeling of a small scale stand-alone wind energy conversion system (WECS) using a maximum power point tracking (MPPT) controller and permanent magnet brushless dc (PMBLDC) generator. The WECS consists of a wind turbine, PMBLDC generator, MPPT controller, isolated half bridge dc-dc converter, battery, voltage source inverter (VSI) and output filter. The fuzzy logic based MPPT controller is designed for a stand-alone WECS for regulating the duty cycle of the dc-dc converter to extract maximum power. The power quality at the consumer load end is maintained using an output voltage controller, which regulates the output voltage and current of VSI. The designed system is modeled and its behavior is simulated in Matlab/Simulink using simpower system and fuzzy logic toolboxes.

The electromagnetic modeling and simulation of existing hydro electrical generators in operation always require a large number of variables to carry out an accurate study and to be able to properly validate the different test results. Simulation can be affected by parameters, such as: the model meshed density; the magnetic materials (magnetic proprieties are usually unknown); the air gap size (the design air gap is always different from the operation air gap due to the thermal expansion) and its uniformity. The excitation current calculated during simulation to achieve the proper line current depends on the air gap and the magnetic properties at the fundamental frequency and its harmonics. This paper reports a FEM simulation of an existing hydro generator of 122.6 MVA, 13.8 kV, 60 Hz, 60 poles with 504 slots, considering the magnetic material, mesh size, air gap length and excitation current as variable inputs. The impact of the modification of these parameters on the electromagnetic finite element simulation is presented, besides, the simulation results were compared with test ones.

This paper presents an implementation of shunt custom power device namely distribution static compensator (DSTATCOM) using a neural network based Anti Hebbian control algorithm for power quality improvement under linear/nonlinear type consumer loads. Learning based Anti-Hebbian control algorithm is used for extraction of fundamental active and reactive power components of load currents in terms of weighted signals which are used for deriving the reference source currents. This control algorithm is implemented on a developed DSTATCOM using a DSP for reactive power compensation, harmonic elimination and load balancing. Simulation and test results demonstrate satisfactory performance of proposed control algorithm for the control of DSTATCOM under time varying loads.

Three simple methods for rotor resistance identification in sensorless indirect field-oriented control of an induction motor drive are presented and compared. Two of the three techniques namely, electromagnetic torque equation, and reactive power are based on the generalization of existing methods. Authors propose the thired method, namely, active power equation which is an improvement over the existing schemes. Although all three schemes estimate the rotor resistance effectively, the proposed technique is superior to others in providing faster estimation approach. The proposed method will be analyzed along with other previously proposed MRAS based methods, and the advantage and limitations of each will be discovered. Simulation results of all three methods will be provided for comparison.

With the new advances in power electronics, and abundance of switched mode power supplies, increasing the reliability of power electronics converters is always being demanded. Lowering the high voltage stresses on the semiconductor components including passive components could contribute to further reliability in power electronics systems. It is due to the fact that lower voltage switches have less on-state resistance and consequently less power losses. Also for the case of transformers, lower voltages on primary means less insulation requirement. This paper proposes a new control strategy called magnetically coupled balancing system which offers a practical solution to cancel the disturbing effect of voltage unbalances across the voltage divider capacitors that are connected in series to the input of each inverter stages. The operational principle, simulation results of the proposed control strategy are to be presented in this paper.

This paper proposes a Lyapunov candidate-based control strategy for three-phases Shunt Active Power Filter (SAPF) to compensate harmonics, reactive power and load unbalance under distorted and unbalanced source voltages conditions. This method determines the control law that makes the derivative of the Lyapunov function always negative for all values of the states. The DC bus voltage of the SAPF is maintained constant by using a proportional-integral regulator. Simulation results are presented to validate the effectiveness of the proposed Lyapunov function-based control scheme.

In this paper, a wind energy conversion system using a Permanent Magnet Synchronous Generator (PMSG) is designed and studied. The output power of the PMSG is supplied to the grid through a switch-mode rectifier followed by a three-phase inverter. The inverter operates as a shunt active power filter to compensate the harmonics, the reactive power, and the unbalance as well as to supply power from PMSG to the grid/load. A novel nonlinear control strategy for the inverter, based on Maximum Power Point Tracking (MPPT) and indirect PQ control is proposed. The control algorithm can be easily implemented in real-time applications, and deals with highly unbalance load and distorted source voltage. The proposed control system avoids the use of high-pass filter that would reduce its steady-state and dynamic performance. A positive sequence detection of source voltage and load current is proposed. The inverter is controlled to achieve balanced sinusoidal grid currents with unity power factor in a large speed range. The control system is simulated using the SimPower blockset of Matlab/Simulink, for a wide variation of the wind speed.

This paper proposes a simple and robust approach to apply the space vector modulation on multilevel inverters. The identification of the adequate triangle in space vector modulation algorithms becomes more complex as the inverter's level increases. Therefore, the problem can be reduced to the selection of a two-level hexagon among many in any sector of the space vector diagram of N-level inverter. The criterion used to select the appropriate hexagon is the minimum distance between the tip point of the reference voltage vector and the center of the hexagon. Once the appropriate two-level hexagon is selected, all the remaining procedures necessary for N-level SVPWM method are thereafter done like conventional two-level inverter. Numerical simulation carried out for three, five and seven level cascaded H-bridge inverters confirms the effectiveness of the proposed method.

This paper proposes a novel configuration of Series hybrid active filters. The proposed configuration could be connected to the grid without requiring a costly series injection transformer. This topology is capable of compensating current harmonics at the source and voltage distortion at the point of common coupling. Furthermore, an appropriate controller could compel the Transformerless hybrid series active filter (THSeAF) to perform as Unified power quality conditioner (UPQC) with quazi-similar behavior. The transformerless configuration is more cost-effective than any other series compensators based mostly on a transformer to inject the compensating voltages. Moreover, as a dynamic voltage regulator, the latter will compensate unwanted harmonics, unbalances, sags, and swells at terminals of a sensitive load. When performing as a series hybrid active filter, it cleans the power system from current distortions together with harmonics and unbalances, similar to a shunt active filter. The detailed operation of the proposed topology is presented and analyzed. Modeling and controller design are given. Validation by simulations of the system dynamic for different load and supply conditions is presented.

This paper presents an advanced comprehensive control approach for Hybrid Series Active Filter (HSeAF). This configuration consists of a series active filter (SeAF) and a shunt passive filter. The proposed control strategy, make this topology capable of compensate current distortions at the source and voltage harmonics and related issues from the load point of common coupling (PCC). The controller compels the HSeAF to perform as Unified power quality conditioner (UPQC) with similar behavior. The control algorithm employs the synchronous reference frames and the p-q theory to create an advanced controller for HSeAFs. This proposed algorithm treats diverse power quality issues simultaneously. With a fast and accurate response, it makes the PCC more reliable, cleans the power system from any current distortions, and also corrects the power factor. Hence, in this paper, the proposed control approach is studied and analyzed by simulations.

The development of active power compensators and power conditioners lead to eminent solutions to improve power quality. Among these emerging solutions, the Series Active Filter is relatively immature compared to shunt and hybrid configurations. This paper presents a comprehensive review of the Series compensator history, configurations, control strategies, and related involvements in this field. It provides a perspective of Series active compensator's technology to researchers dealing with power quality issues. This paper tries to promote industrial application of series compensators for future Smart grids.

In this paper, an overview of active power electronics devices, dedicated to the compensation of current harmonics that are generated by the proliferation of nonlinear connected to the distribution power grids, is presented. A special attention will be brought on the discussion of Power Factor Correction (PFC) circuits commonly used in single-phase applications, and single-stage active rectifiers dedicated to the three-phase case. Active and hybrid power filters will also be briefly presented. The study will focus more specifically on the current tracking ability of the considered topologies, DC voltage regulation, performance limitations, design considerations, modeling processes, control complexity, voltage stresses and power efficiency. Other derived structures for high current applications and high power efficiency will also be discussed.

In this paper, a study of a two-stage regenerative grid-connected AC-DC power module for load emulation is presented. It consists of an active rectifier connected with a dual active bridge. Both conversion stages are designed and controlled in order to ensure power factor correction at the AC side and a regulated voltage at the DC side. The development of the control system is based on the small-signal transfer functions of the converter, which are computed the average modeling technique. A 5 kW module is used as a base to design and simulate such system. The steady-state and dynamic behavior of the converter is tested under varying operating conditions, and the stability of the interconnection between the two conversion stages is discussed.

This paper presents the design of a Linear Quadratic Regulator (LQR) with Integral action (LQRI) applied to a grid connected wind energy conversion system (WECS) based on squirrel cage induction generator (SCIG) with full-capacity power converter (WECS-SCIG). The controller is used to achieve speed regulation for maximum power extraction from the wind turbine, DC bus voltage regulation and to keep the power factor at unity for the grid-side converter. The model of this latter is set in the d-q rotating reference frame synchronized with phase a of grid voltages while rotor flux oriented vector control is used for the machine-side converter. Knowing that the standard LQR provide essentially proportional gains, the system dynamic is augmented with the integral of the q component of the grid currents, the rotor flux, the DC bus voltage and the generator speed in order to cancel steady-state errors. The WECS-SCIG is controlled as a whole i.e. a multi-input-multi-output (MIMO) system and a fixed PWM at 2.7 kHz is used to generate the gating signals of the two back to back converters. The system is tested for both steady-state and in transient for a sudden variation in wind speed. The simulation results obtained with SimPowerSystems (SPS) and Simulink of Matlab implementation of the controller proved the effectiveness of the control strategy.

In this paper, authors propose a novel current control suitable for the three phase five-level PUC-NPC converter. The later was introduced in previous papers, it results from a topological optimization of a series connection of two three level PUC and NPC converters. The PUC-NPC topology is characterized by the use of only six power switches per phase in the case of five level converter. Modeling of the proposed PUC-NPC rectifier and a novel current control associated to a novel balancing technique are performed in order to draw a nearly sinusoidal lines currents and line-to-line voltages with a unity power factor operation. The balanced DC link and auxiliary output voltages insure the protection of loads, passives and actives power devices. The proposed PUC-NPC three phase five level rectifier associated to the proposed control and balancing techniques were verified by simulation.

In recent years, hybrid power filters (HPF) have been widely investigated for power quality improvement. They are used to compensate for harmonics and reactive power as well as for balancing unbalanced non-linear loads under non-ideal mains voltage conditions. This paper deals with a comprehensive review of hybrid power filter topologies and harmonic extraction methods. Classified references on the state of art of HPF presented in this paper would serve for a quick reference.

This paper proposes a three-phase current controlled power inverter for both photovoltaic (PV) power grid injection and power quality improvement. The inverter operates as a shunt active power filter (APF) to compensate the unbalances, harmonics, reactive power and supply voltage fluctuations. It supplies simultaneously the power from the PV array to the load and the grid. The PV source is connected to the active power filter by an intermediate boost dc-dc converter which is controlled using the Maximum Power Point Tracking (MPPT) technique. The MPPT controller's output determines the DC-bus voltage of the inverter according to PV maximum power. A nonlinear control scheme is proposed for the inverter in order to compensate the source voltage unbalance, the source voltage fluctuations, the current harmonics, the reactive power and the load unbalance. It avoids the use of passive filters that could affect severely the performance of the compensation system and slow down the dynamic response of the system. A bidirectional buck/boost converter is used to control the battery charging and discharging, which is essential in hybrid electrical vehicles or grid back-up sources during peak demand of energy. A combination of linear inductive load with single-phase and three-phase diode bridge rectifiers connected to DC R-L loads is considered. Simulation results that demonstrate the viability and effectiveness of the proposed configuration are presented and discussed.

This paper discusses the track layout of a light rail vehicle application (LRV) to be simulated along with an Energy Storage System (ESS) aiming to counteract voltage sags. It also describes the train modeling technique used in a train run simulator and a network simulator including the ESS. It compares experimental results with simulation. A sensitivity analysis to ESS and algorithm parameters is performed.

A practical concern with implementing the fixed band hysteresis current control in active power filters (APF) is its variable switching pattern that results in increasing the risk of occurrence of resonance in power systems. To avoid this situation, adaptive hysteresis current control methods with the variable hysteresis bands have been recommended in literature. However, these methods impose an absolutely huge amount of complex computations on the system which, in turn, slows down its response time and thereby, limits the switching frequency. This paper devises a novel fixed-band fixed-frequency (FBFF) hysteresis current control strategy that aims to eliminate completely the mentioned calculations while keeps merits of the adaptive methods. In other words, the suggested strategy employs an algorithm that is similar to the fixed-band variable-frequency hysteresis methods; however, the outcomes are identical to the variable-band fixed-frequency hysteresis current control techniques. Employing the proposed FBFF method to control an APF leads to an accurate modulation performance with the least possible calculations required in a filtering procedure. Several simulations are done using MATLAB/Simulink to verify validity of the proposed method.

Solid-state switch mode AC-DC converters having high-frequency transformer isolation are developed in buck, boost, and buck-boost configurations with improved power quality in terms of reduced total harmonic distortion (THD) of input current, power-factor correction (PFC) at AC mains and precisely regulated and isolated DC output voltage feeding to loads from few Watts to several kW. This paper presents a comprehensive study on state of art of power factor corrected single-phase AC-DC converters configurations, control strategies, selection of components and design considerations, performance evaluation, power quality considerations, selection criteria and potential applications, latest trends, and future developments. Simulation results as well as comparative performance are presented and discussed for most of the proposed topologies.

The study of the degraded mode is of high importance in proposing diagnosis strategies. Hence the use of a precise modelling of the power electronic components is necessary to make good simulations. The paper presents an advanced IGBT model based on the functional description of a complete model which covers linear, saturation and breakdown modes. Several simulations are presented to show its validity in the static and dynamic behaviours. The comparison between the Matlab Power Blockset model and the proposed one proves the reliability of our approach.