Analysis of carrier based PWM methods in relation to common mode voltage for multilevel inverter

Abstract

This paper presents a new approach to implement a carrier based PWM modulator in a multi-level inverter, using correlation between carrier based PWM and space vector PWM. Using the performed relation, different CPWM methods in a multilevel inverter can be simply clarified and appropriately modified for obtaining required performance. In this paper, the principle of carrier based PWM with medium and minimum common mode voltage and possible variants of implementation is introduced. It also shows several advantages from the minimum common mode voltage methods. The proposed CPWM modulator algorithms are advantageous for the simplicity and flexibility to apply to a high level inverter.