Performance Investigation of Multi-Phase VSI with Simple PWM Switching Techniques

Abstract

This paper presents the performance investigation of multi-phase voltage source inverter (VSI) with simple PWM switching techniques namely the harmonic injection and offset injection method. The technique discussed in this paper is easy to implement and avoid complicated controlling algorithm adapted in SVPWM technique. A generalized algorithm suitable for odd number of phases is developed in Matlab/Simulink environment and discussed in detail for both the switching methods. The performance of the 5, 7 and 9-phase VSI is studied with the above said switching methods. The simulation results are presented for different modulation indices and a comparison in terms of fundamental voltage and THD identifies the better scheme suitable for multi-phase inverter fed drives.