Pulse Switching Shock Suppression Method of PWM Inverter for Pole-Changing Induction Motor

This paper proposes a pulse switching shock suppression method for a PWM inverter, which consists of two original approaches: (i) a switching method between a synchronous and an asynchronous carrier-based PWM during pole-changing and (ii) a pulse pattern switching method of the synchronous PWM, for a pole-changing induction motor. Continuous changes in harmonic components are confirmed by the proposed method, which suppresses the switching shocks in the analysis and experiment.