A technical review of modern traction inverter systems used in electric vehicle application

Abstract

This article presents a comprehensive review of modern traction inverter systems, their possible control strategies, and various modulation techniques deployed in electric vehicles (EVs). The traction inverter is a fundamental component in electrifying the EV drive system due to its critical functioning in a wide range of operations. Some well-known EV manufacturers have recently switched to high-voltage rating batteries in order to gain the advantages of lower current, greater density of power, and quicker charging state time. In this context, multilevel inverters (MLIs) have taken on the role as a promising substitute of traditional two-level traction inverters, and using suitable control and modulation techniques becomes crucial for employing multilevel systems. Many important problems that arise in multilevel topologies, such as equal power loss sharing and capacitor voltage balancing must be handled by the control system structure. Additionally, MLIs possess benefits such as increased efficiency, improved quality of waveform, and inherent fault tolerance, which make them a desirable choice for EV applications. A comparison of various MLI topologies is presented in this paper based on the most significant factors considered in the electrification of transportation. The objective of this article is to explore the various aspects of MLI concepts including alternative topologies, with lower switch counts.