An Asymmetric Switched-Capacitor Multicell Inverter With Low Number of DC Source and Voltage Stress for Renewable Energy Sources

Mohammad Ali Hosseinzadeh,Cristian F. Garcia,Maryam Sarebanzadeh,Jose Rodriguez,Ebrahim Babaei

doi:10.1109/access.2022.3140786

Abstract

Asymmetric multilevel inverters generate high-quality output voltage using the same number of components as symmetric multilevel inverters. The main drawback of these topologies is that they require many DC voltage sources, and the power switches must endure high voltage stress. In this paper, a switched-capacitor sub-module inverter topology is proposed to reduce the number of DC voltage sources and the voltage stress on the switches of asymmetric multilevel inverters. The proposed sub-module inverter can generate 15 voltage levels by using two DC power supplies and a capacitor. The voltage of the capacitor can be automatically charged at half of the input DC power supply without the need for any sensors. In addition, the capacitor charging operation does not produce an inrush current because it is charged by the direction of the output current; this is an advantage over switched capacitor multilevel inverters. A modular topology is also presented based on the proposed sub-module inverter to achieve high voltage levels while reducing the number of elements. A comprehensive comparison between the proposal and other multilevel inverter topologies is performed to validate the design of the proposed inverter. In addition, thermal and loss distribution simulations of the proposed sub-module inverter are performed. Finally, the performance, efficiency, and accuracy of the proposed inverter are confirmed through laboratory prototyping.

Highlights

D UE to the long-term incompatibility of standard twolevel inverters, Multilevel Inverters (MLIs) have become an unavoidable power electronics device in a wide range of modern power conversion applications
Multilevel inverters can generate higher voltage levels using low-nominal voltage switches. These advantages have made multilevel inverters broadly employed in industry, including Renewable Energy Sources (RES), Variable Frequency Drive (VFD), UPS systems, reactive power compensators, Electric Vehicles (EVs), etc. [4]-[6]
The proposed topologies are general topologies, similar to existing multilevel inverter topologies that may be used with renewable energy sources (PV and wind), Electric Vehicles (EVs), FACTS, and so on

Summary

INTRODUCTION

D UE to the long-term incompatibility of standard twolevel inverters, Multilevel Inverters (MLIs) have become an unavoidable power electronics device in a wide range of modern power conversion applications. To produce a 13-level inverter, [14]-[18] have the advantage of boosting the output voltage, but they still require a large number of switches, driver circuits, and capacitors, which decrease the efficiency and increase the overall cost and control complexity of the multilevel inverter. The proposed MTTC inverter decreases the number of capacitors and can be charged with the load current based on the Apmer-second rules of capacitor voltage It does not require any voltage balancing control technique or any sensor to measure its value. In this case, the capacitor voltage is discharged if the load current (iL > 0) and it is charged if (iL < 0).

C: Discharge

15 NIGBT 9

H Bridge

COMPARISON OUTCOMES

CONCLUSION