This article presents a new dynamic boosting seven-level grid-connected transformerless inverter topology with dual ground. The dual ground design reduces leakage current, which makes it appropriate for solar photovoltaic systems. The proposed topology incorporates the integrated boost and switched capacitor cells, producing a 7L output voltage waveform. The proposed topology features less component count and low stress on switches and is suitable for a wide range of input voltage fluctuations. A detailed mathematical analysis, operating modes, and passive components design are presented. Also, a comprehensive power loss analysis with efficiency for different power ratings is discussed. The feasibility study was done in MATLAB, and the same was validated in a 1-kVA laboratory test bench. The reported rms leakage current is <1 mA, which is within the limits of the VDE-00126-01 standard. Finally, the experimental results are discussed, and a detailed comparison with recent topologies is presented.

Dynamic wireless power transfer (DWPT) for charging electric vehicles (EVs) has recently seen widespread interest and adoption. Despite this progress, the technology still encounters challenges, such as output voltage fluctuations and high copper costs for the charging infrastructure. While a well-designed receiver coil can help minimize these fluctuations, they tend to worsen as vehicle speed increases. To address these issues, a DC-DC converter with closed-loop control is proposed. This converter, a boost-type with extendable gain, incorporates a PI controller to regulate output voltage in response to changes in vehicle speed. The system’s performance is validated through MATLAB Simulink simulations, achieving up to 98% efficiency under varying loads and maintaining 93% efficiency during dynamic EV operation.

This work proposes an adaptive predictive control scheme with online parameters identification to mitigate the inductive filter parameter mismatch in grid-connected inverters. The effect of the parametric mismatches on the current prediction error and the stability of the closed loop control system is investigated. The predictive current controller is implemented in a rotary reference frame following the voltage-oriented control (VOC) principle. The dc components of the grid current in the d-q reference frame during steady-state allowing an easy implementation of the recursive least squares estimator in order to estimate the filter inductance and resistance parameters. The estimated parameters online are transmitted to the predictive current controller to accurately calculate the output predictions and generate the optimal control action. As a result, the inherent sensibility of the predictive controller to the parameters mismatch is avoided. The effect of the weighting factor of the recursive least squares estimator on the controller performance is discussed.

Electricity outages can result in consequences for customers and cause disruptions that result in revenue loss, business productivity reduction, appliance damage, and compromised public safety. To minimize outage duration, locating faults quickly and accurately is crucial. Advanced fault management strategies leverage computational intelligence and deploy fault indicators (FIs) and sectionalizing switches (SSs) to locate faults and isolate faulty parts. Although FIs and SSs can improve distribution network reliability, deploying them at every node is impractical owing to cost and complexity. Therefore, it is important to optimize their placement in strategic locations. This research proposes a new optimization problem for the simultaneous placement of FIs and SSs. The aim is to minimize the cost of equipment placement, dispatching field crews, and service interruption. To solve the proposed formulation, the Backtracking Search Algorithm (BSA), a population-based meta-heuristic method, is used to identify optimal nodes for FIs and SSs placement. The performance of the BSA is evaluated through statistical tests, and the proposed strategy is shown to be effective compared to state-of-the-art methods. The results reveal a significant 7% reduction in device requirement, leading to a substantial 6.69% decrease in equipment expenditures and an overall decline in system costs compared to the established approach implemented in the test system. This research highlights the importance of optimization strategies for fault management systems and demonstrates the potential of meta-heuristic algorithms for solving complex problems.

This paper proposes a dynamic wireless power transfer system with an overlapped QQ receiver. The proposed coupler is analyzed, and the simulation results of this system is presented. It's observed that the proposed coupler has lower mutual inductance variation in misalignment compared to a single receiver system. When one receiver receives lowest power, another receiver receives highest power at that position and together both receiver helps to improve performance of the system. To verify the feasibility of proposed coupler finite element analysis (FEA) software Ansys Maxwell is used. The variation of mutual inductance for the proposed coupler is found ± 2.38%. This proposed coupler also increase the mutual inductance hence increases the output power. The simulation results of the proposed system are also presented in this paper.

This paper proposes and experimentally implements new phase-locked loop algorithms using non-adaptive and adaptive terminal sliding modes for the three-phase grid-connected inverters. The proposed algorithms aim to extract the grid voltage phase and frequency and provide them for the inverter controller. The proposed sliding mode-based PLL algorithms provide faster, more robust, and more accurate detection of the grid voltage information compared to the conventional PI-PLL. This leads to better current controller performance and subsequently, improves the quality of the injected currents into the grid. The finite-time stability notion is incorporated with robust sliding modes to ensure a fast convergence rate. An adaptive law is proposed to determine a proper value for the switching gain which leads to a better overall performance of the PLL compared with a non-adaptive one. The Lyapunov stability theory is used to obtain the stability proofs of the closed-loop systems under both designed sliding modes-based PLLs. The proposed PLL algorithms are validated by simulation and experimental results for the three-phase grid-connected inverter under normal and various abnormal grid conditions.

This brief reports a dual-topology CMOS rectifier with an extended power dynamic range (PDR) for radio frequency (RF)-based hybrid energy harvesting (RF-HEH) systems. By leveraging both the cross-coupled differential drive (CCDD) and the Dickson topologies with high forward conduction and low reverse leakage, we obtain an extension of the rectifier’s PDR by adaptively disabling the CCDD counterpart and enabling the Dickson counterpart to dominate the rectifier’s performance during high-power operation. Apart from that, we formulate a rectifier-performance index (RPI), which accounts for the power conversion efficiency (PCE), the PDR, the sensitivity, and the load resistance of the rectifier to provide an adequate performance benchmark with the state-of-the-art rectifiers. Fabricated in a 130-nm CMOS, the proposed dual-topology rectifier measures a wide PDR of 19.5 dB with a peak PCE of 78.4% for a 100-$\text{k}\Omega $load operating at 900 MHz. Besides, our prototype records the highest RPI of 19.2 compared to the recent arts operating at GSM900.

This brief presents a novel circuit architecture for a Dickson-based reconfigurable rectifier with wide power dynamic range (PDR). Besides, a novel figure of merit (FoM) concerning the reconfigurable rectifiers is formulated to provide a more comprehensive assessment of the rectifier’s performance. The proposed reconfigurable design improves the operating range of the rectifier by adaptively switching between the six-stage configuration during low-power operation and the 12-stage configuration during high-power operation. Fabricated in 130-nm CMOS, the proposed reconfigurable rectifier measures a PDR of 14 dB with a peak power conversion efficiency (PCE) of 34.93% for 1-$\text{M}\Omega $load operating at 900 MHz. Relative to the recently published reconfigurable rectifiers, our design records the highest FoM of 36.98 dB/mm2, with minimum harvesting downtime.

This paper proposed a new single-phase single stage single source nine-level boost inverter topology with self-voltage balancing along with the reduce switch count. The proposed topology is aimed to design for the renewable energy sources interfacing to the loads, which require higher voltage magnitudes. The proposed topology gives twice voltage booting feature without using any dc-dc converter. The topology proposed in this paper uses a single dc voltage source with two capacitors to generate a nine-level output voltage waveform. Nearest level control modulation technique has been used for the generation of gate pulse for the different switches used in the proposed structure. Different simulation results have been provided using PLECS software, and these simulation results have been verified using the experimental results obtained from a laboratory prototype.

Photovoltaic arrays subject to partial shading conditions have more than one maximum power point (MPP), and conventional algorithms are unable to track the global maximum power point (GMPP) accurately. Thus, an improved global search space differential evolution algorithm for tracking the GMPP is introduced in this paper. The main contribution of the proposed algorithm are the following: capability in tracking GMPP and faster respond against load variation; optimization algorithm can search for the GMPP within a larger operating region as it is implemented by using a single-ended primary-inductor converter; and easy tuning as less parameter has to be set in the algorithm. The proposed system is first simulated in PSIM to ensure its capability. The feasibility of the approach is validated through physical implementation and experimentation. Results demonstrate that the proposed algorithm has the capability to track the GMPP within 2 s with an accuracy of 99% and respond to load variation within 0.1 s.

Global demand for power has significantly increased, but power generation and transmission capacities have not increased proportionally with this demand. As a result, power consumers suffer from various problems, such as voltage and frequency instability and power quality issues. To overcome these problems, the capacity for available power transfer of a transmission network should be enhanced. Researchers worldwide have addressed this issue by using flexible AC transmission system (FACTS) devices. We have conducted a comprehensive review of how FACTS controllers are used to enhance the available transfer capability (ATC) and power transfer capability (PTC) of power system networks. This review includes a discussion of the classification of different FACTS devices according to different factors. The popularity and applications of these devices are discussed together with relevant statistics. The operating principles of six major FACTS devices and their application in increasing ATC and PTC are also presented. Finally, we evaluate the performance of FACTS devices in ATC and PTC improvement with respect to different control algorithms.

Under fast-varying solar irradiation and load resistance, a fast-converging maximum power point tracking (MPPT) system is required to ensure the photovoltaic (PV) system response rapidly with minimum power losses. Traditionally, maximum power point (MPP) locus was used to provide such a fast response. However, the algorithm requires extra control loop or intermittent disconnection of the PV module. Hence, this paper proposes a simpler fast-converging MPPT technique, which excludes the extra control loop and intermittent disconnection. In the proposed algorithm, the relationship between the load line and the I-V curve is used with trigonometry rule to obtain the fast response. Results of the simulation and experiment using single-ended primary-inductor converter showed that the response of the proposed algorithm is four times faster than the conventional incremental conductance algorithm during the load and solar irradiation variation. Consequently, the proposed algorithm has higher efficiency.

Three-stage 18-level hybrid inverter design with novel control method is presented. The inverter consists of main high-, medium-, and low-voltage stages connected in series from the output side. The high-voltage stage is a three-phase, six-switch conventional subinverter. The medium- and low-voltage stages are made of three-level subinverters constructed by H-bridge units. The proposed control strategy assumes a reference input voltage vector and aims to approximate it to the nearest inverter vector. The control concept is based on holding the high-voltage state as long as it is feasible to do so. The reference voltage vector has been represented in a 60°-spaced two axis coordinate system to reduce the computational effort. The concept of the staged-control has been presented, the transformed inverter vectors and their relation to the switching variables have been defined, and the implementation process has been described. The test results verify the effectiveness of the proposed strategy in terms of computational efficiency as well as the capability of the inverter to produce very low distorted voltage with low switching losses.

Three-stage redundancy-free multilevel inverter and its innovative control method have been presented. Logic comparators have been implemented in order to ease calculations and to ensure simplicity as well as to improve resultant voltage waveforms. The multistage inverter is formed by high, medium and low voltage stages, connected in series. Six-switch conventional inverter represents the main high- voltage stage. Cascaded H- bridge units are used to build the medium and low voltage stages of the inverter. The proposed control strategy is to keep the state of the high voltage stage if it can lead to the target voltage vector or medium and low approximations otherwise, are triggered. Hysteresis Comparators are used in high and medium voltage stages to hold switching states or to decide the next change. The low voltage stage works to reach the reference voltage vector by using integer rounding and comparators to achieve the best approximations. The designed control technique is verified by simulations as well as testing to prove its advantages over previous control methods.