Reducing root-mean-square current stress on the DC link capacitor of a five-phase electric drive through multiple carrier pulse-width modulation technique

This study investigates the angle of phase shift between interleaved carriers in pulse-width modulation, as an additional design parameter to reduce the DC link stress of a five-phase drive. Several phase shift strategies are studied and defined with a focus on the DC link root-mean-square current. The effect of adjusting the phase shift between interleaved carriers on the DC link stress is analysed and a general mathematical model is proposed to estimate the effect for any phase shift strategy. The trends predicted by simulations and analytical models have been validated through the application of the control algorithm on a five-phase motor drive system.