Parallel switch‐based chopper circuit for DC capacitor voltage balancing in diode‐clamped multilevel inverter

Abstract

In recent years, the multilevel inverters have become a practical solution for high-voltage application and power quality issues. In all multilevel topologies with several DC links, the voltage balancing of DC capacitors is known as a key problem. In this study, a novel topology of chopper circuit for DC capacitor voltage balancing in diode-clamped multilevel inverters (DCMLIs) is proposed. Presented topology has less number of switches with respect to other proposed topologies in literatures. Suggested topology is modular and has high reliability. Based on the presented control system for chopper switches, only one switch is turned on at each interval. Therefore the conduction and switching losses of the chopper circuit are reduced. Referring to the simulation results, fast dynamic response of suggested chopper and reduction in voltage stress on switches can be seen clearly. Computer-aided simulations are performed through MATLAB Simulink software. A prototype chopper circuit has been implemented and tested. The experimental results are also presented to verify the performance of the proposed chopper circuit and its control system for DC capacitors voltage balancing in DCMLIs.

Five-Level PWM Inverter Using Series and Parallel Alternative Connection of Batteries

“…When a circuit employs series-connected capacitive components, sometimes it has a voltage unbalance problem because of different charging and discharging periods. Thus, voltage balancing control is required to maintain voltage in a constant value [20][21][22][23]. Although the proposed 5-level PWM inverter also uses series-connected batteries, it does not need to consider on voltage unbalancing problem since both batteries have the same time for charging and discharging.…”

A New Diode-Clamped Multilevel Inverter for Capacitor Voltage Balancing

“…2. It can balance the voltages of capacitors with simple control system with only two inductors incorporated, which is an extraordinary advantage compared with the aforementioned methods in [16][17][18][19][20][21][22]. …”

“…Let's denote the point n as neutral reference, and the output voltage of the inverter has five levels. For the convenience of theoretical analysis, it is assumed that all the switches are ideal, C 1 = C 2 = C 3 = C 4 = C, and the load is a resistor R. [22][23][24][25]. In mode (c), i 3 = 0 and does not cause voltage unbalance.…”

“…1(c)) [19][20][21], or parallel switch-based chopper circuit (PSBC) ( Fig. 1(d)) [22]. All these methods need hardware reconfiguration.…”

Improved SHEPWM Strategy By The Robustness Optimization Algorithm In Multilevel Inverters With Equal DC Sources

“…The most common topologies which are used in the prior article for multilevel inverter are included cascaded full bridge structure [7][8][9], the diode clamped structure [10] and flying capacitor structure [11]. The full-bridge structure needs fewer components to produce the same output waveform.…”