An Asymmetric Switched Capacitor Multilevel Inverter With Component Reduction

Asghar Taheri,Ahad Rasulkhani,Hai-Peng Ren

doi:10.1109/access.2019.2938980

Abstract

This paper proposes a new switched capacitor (SC-Type) inverter for asymmetrical multilevel inverters (MLIs) with fewer components. In order to balance the voltages of the capacitors, the proposed topology uses a special method to charge/discharge the capacitors. In the proposed inverter, the number of switches, the number of dc voltage sources, the amount of blocked voltage in the switches, and the power losses are reduced. Fewer components result in lower size, complexity, and cost of MLI. Cascade connection of the proposed topology is used to achieve a higher number of output voltage levels. The MATLAB simulations and experimental results of a 25-level MLI verify the good performance of the proposed inverter.

Highlights

Multilevel inverters (MLIs) have been interested as necessary devices with a wide range of applications which growingly affect the power electronics
An MLI is formed by different arrangements of semiconductor switches and dc links to generate n-level output waveforms, which are divided into three main classifications [12]–[14]: neutral point clamped (NPC) [15], flying capacitor (FC), and cascaded H-bridge (CHB)
In this paper, a novel topology of asymmetrical configuration of MLI is proposed for a wide range of application such as reactive power compensators, adjustable-speed drives, uninterruptible power supplies, PV systems and solar energy systems

Summary

INTRODUCTION

Multilevel inverters (MLIs) have been interested as necessary devices with a wide range of applications which growingly affect the power electronics. Each proposed basic unit consists of two unequal dc sources, four capacitors, six unidirectional and four bidirectional switches and produces 25 levels in output voltage. Another condition for capacitor voltage balancing is that both capacitors C1 and C2 (or C3 and C4) be charged .

COMPARISON OF THE PROPOSED INVERTER WITH OTHER TOPOLOGIES

CONDUCTION LOSSES

SWITCHING LOSSES

EXPERIMENTAL AND SIMULATION RESULTS

EXPERIMENTAL AND SIMULATION RESULTS OF 25- LEVEL INVERTER

CONCLUSION