This paper introduces a new configuration of bi-directional multilevel converter in electric vehicle (EV) applications. It has multilevel DC-DC converter with a direct current (DC) link capacitor voltage balance feature. The multilevel DC-DC converter operates in bi-directional manner, which is a fundamental requirement in EVs. Compared to the conventional configurations, the proposed one only implements two extra power switches and a capacitor to balance the voltage of the T-type MLI capacitor over a complete drive cycle or at fault conditions. Therefore, no extra isolated sensor, control loops and/or special switching pattern are required. Moreover, the proposed configuration due to the high frequency cycle-by-cycle voltage balance between $C_n$ and $C_p$ the bulky electrolytic capacitors used in T-type MLI are replaced with longer life more reliable film capacitors. This will result in a size and weight reduction of the converter by 20%. This allows more real estate for the EV battery in the chassis' space envelope; to increase its capacity. The proposed configuration is tested and validated using a Matlab/Simulink simulation model. A laboratory prototype 1 kW is built to provide the proof of concept results as well.

This study proposes a new two‐stage high voltage gain boost grid‐connected inverter for AC‐module photovoltaic (PV) system. The proposed system consists of a high‐voltage gain switched inductor boost inverter cascaded with a current shaping (CS) circuit followed by an H ‐bridge inverter as a folded circuit and its switches operate at line frequency. The switched inductor boost converter (SIBC) has one switch operates like a continuous conduction mode. The maximum power of the PV module is achieved through the SIBC circuit whereas the grid connection requirements are accomplished using the CS circuit with the H ‐bridge inverter. The switch of the CS circuit is controlled with a sine wave modulation control scheme. The main advantages of the new proposed system are high boosting gain, lower switching losses and reduces the ground leakage current as all H ‐bridge switches operate at the line frequency. A 120 W prototype has been built and experimentally tested. It has been found that experimental results have a good matching with the proposed analysis and simulation results.

This paper presents a new boost inverter topology with nine level output voltage waveform using a single dc source and two switched capacitors. The capacitor voltages are self-balancing and thus is devoid of any sensors and auxiliary circuitry. The output voltage is twice higher than the input voltage, which eliminates the need for an input dc boost converter especially when the inverter is powered from a renewable source. The merits of the proposed topology in terms of the number of devices and cost are highlighted by comparing the recent and conventional inverter topologies. In addition to this, the total voltage stress of the proposed topology is lower and have a maximum efficiency of 98.25%. The operation and dynamic performance of the proposed topology have been simulated using PLECS software and are validated using an experimental setup considering a different dynamic operation.

Today, a predictive controller becomes one of the state of the art in power electronics control techniques. The performance of this powerful control approach will be pushed forward by simplifying the main control criterion and objective function, and decreasing the number of calculations per sampling time. Recently, predictive control has been incorporated in the Z-source inverter (ZSI) family. For example, in quasi ZSI, the inverter capacitor voltage, inductor current, and output load currents are controlled to their setting points through deciding the required state; active or shoot through. The proposed algorithm reduces the number of calculations, where it decides the shoot-through (ST) case without checking the other possible states. The ST case is roughly optimized every two sampling periods. Through the proposed strategy, about 50% improvement in the computational power has been achieved as compared with the previous algorithm. Also, the objective function for the proposed algorithm consists of one weighting factor for the capacitor voltage without involving the inductor current term in the main objective function. The proposed algorithm is investigated with the simulation results based on MATLAB/SIMULINK software. A prototype of qZSI is constructed in the laboratory to obtain the experimental results using the Digital Signal Processor F28335.

This paper presents a new design and implementation of a three-phase multilevel inverter (MLI) for distributed power generation system using low frequency modulation and sinusoidal pulse width modulation (SPWM) as well. It is a modular type and it can be extended for extra number of output voltage levels by adding additional modular stages. The impact of the proposed topology is its proficiency to maximize the number of voltage levels using a reduced number of isolated dc voltage sources and electronic switches. Moreover, this paper proposes a significant factor (FC/L), which is developed to define the number of the required components per pole voltage level. A detailed comparison based on FC/L is provided in order to categorize the different topologies of the MLIs addressed in the literature. In addition, a prototype has been developed and tested for various modulation indexes to verify the control technique and performance of the topology. Experimental results show a well-matching and good similarity with the simulation results.

This paper proposes a new method to calculate switching angles in selective harmonic elimination technique. It is introduced as a substitute for Newton-Raphson method and similar iteration methods. By utilizing classical control such as the proportional-integral (PI) control, the proposed method can perform a real-time calculation for multilevel inverter's (MLI) switching angles over a wide range of modulation indexes. Therefore, it is able to respond to system dynamics without the need to store precalculated large lookup tables. The proposed method is applied to seven levels cascaded full H-bridge to eliminate its third- and fifth-harmonic contents from the modulation index 0.1 to 1.04. The same procedure can be extended to the vast majority of MLI topologies. A Simulink model is built to simulate and validate the accuracy, dynamics, and continuity of the solution generated by the proposed method. An experimental prototype is also built and its results are discussed to confirm the theory and simulation of the proposed method.