Harmonic Current Suppression Method of Asynchronous Motor Based on Nonzero Vector Pulse Width Modulation

Abstract

Nonzero vector pulse width modulation (NZPWM) suppresses the common mode voltage (CMV) at the output of asynchronous motor drive system, but this modulation strategy causes an increase in the output harmonic current content, which adversely affects the system performance. Therefore, in order to make the NZPWM strategy suppress the CMV without adversely affecting the system performance. In this paper, a harmonic current suppression method of asynchronous motor based on NZPWM is proposed. The proposed method is able to effectively suppress both the low order current harmonic and the high order harmonic currents near integer multiples of the switching frequency. Finally, the simulation analysis shows that effective reduction of harmonic currents at low frequency orders and multiples of the switching frequency, and lower total harmonic distortion (THD) values are achieved. The result verifies the correctness of the theoretical analysis and the feasibility of the proposed method.