Novel PWM technique for nth harmonic injection for N-phase VSIs

Abstract

This paper presents the novel PWM technique for nth harmonic injection for n-phase VSIs. Multi-phase voltage source inverters are dominantly used to supply the multi-phase drives which are used for high power applications. Multi-phase induction motor drive possess several advantages over conventional three-phase drive, such as reduced current per phase, increased power in the same frame and high torque frequency etc., The technique discussed in this paper is easy to implement and avoid complicated controlling algorithm adapted in SVPWM technique. The generalized switching technique is proposed in this paper. A generalized algorithm suitable for odd number of phases is developed in Matlab/Simulink environment and discussed in detail. The performance of the 5, 7 and 9-phase VSI is studied with the above said switching method. The VSI fed multi-phase drive is analyzed. The simulation results are presented for different modulation indices and compare the performance of the drives are presented.