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.

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.

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.

This paper presents a detailed review on different architecture topologies for Electric Vehicle (EV) charging station. The proposed paper enables to have a solid reference on electric transportation charging station topologies on different levels starting from the infrastructure of common bus to types of chargers and power flow uni/bi-directionality. Besides, two detailed comparative analyses on recent proposed EV architecture topologies based multilevel converters as Cascaded H-Bridge (CHB) and Neutral Point Clamped (NPC) converters are elaborated. The presented CHB analysis tackles enhancements’ attempts on charging time, balancing batteries’ State-Of-Charge (SOC), reducing power losses and balancing capacitors’ voltages. However, the presented NPC analysis includes attempts in improving NPC’s limited voltage balance operation, balancing the bipolar DC bus, regulating load disturbances, enhancing power quality and power utilization. The two analyses are summarized in two comparison tables to sum up the aim and the enhancement of each presented attempt.

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.

This paper discusses the state of the art of different topologies of Modular Multilevel Converters (MMC) used in Electric Vehicle (EV) power-train. A comparative study of recently proposed MMC used as a propulsion application in EV is elaborated here for the first time in EV research field. First, this paper delivers a general overview on multilevel converters associated with their various types and advancements. Then, it discusses the change from Internal Combustion Engine Vehicle (ICEV) to EV. Finally, it conducts a comparative study on the existed MMC topologies by categorizing them into five sections according to their types and contribution. First section includes the topologies that follow the same MMC architecture of cascaded half bridges. Second section discuses topologies consisting of cascaded H-bridge (CHB) and points any recorded contribution in comparison with conventional topologies. Third section focuses on topologies that reduces switching elements significantly making the whole system more reliable, cost competitive, more efficient and more size compressed. Fourth section tackles topologies with hybridized energy storage system using Ultra-Capacitors (UC) in order to track its impact on power density limitation. Last section adopts hybridized multilevel converters to observe its effect on system's efficiency and switching losses. The contribution of this paper is pointing on the strength and weakness of each topology in terms of fault tolerance, balance control, size, reliability, efficiency, cost, power density, mobility range, switching elements and switching losses.

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.

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 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.

The fluctuations in the power delivered to the grid remain a problem in photovoltaic grid-connected systems. Energy storage systems are proposed as a solution in order to comply with these standard power quality requirements. Due to their distinctive properties, supercapacitors can be considered as the most efficient energy storage systems available in the market today. Thus, their capability of fast charging and discharging and their high capacitance (hundred of farads) compared to the traditional ones have been the main reason of their massive integration in PV systems. This paper presents a comparison between a conventional capacitor and a supercapacitor used as DC-link in a PV grid connected system. The superiority of the supercapacitor is demonstrated through a performance evaluation based on simulation results.