Torque ripple suppression strategy of asynchronous motor for electric vehicle based on random pulse position space vector pulse width modulation with uniform probability density

Abstract

Abstract A random modulation strategy is proposed to suppress the torque ripple of asynchronous motor for electric vehicle in this article. First, the models of harmonic torque and torque ripple are established. The reason of harmonic generation and its effect on torque are analysed. Second, the random position pulse width modulation (PWM) strategy with different random quantities is introduced. The problem of the increasing harmonic content near the integer multiple of the switching frequency in the modulation process is solved. Subsequently, the influences of different random quantity distributions and random number ranges on harmonic suppression are studied. The different structures of random pulse position space vector PWM strategy based on uniform probability density are designed. The specific harmonic content is dispersed and the torque ripple is suppressed. Finally, the precise test platform based on cSPACE is established. The influence of different random PWMs on motor at various speeds is compared. Experimental results verify the validity of the proposed approach.

Keywords

• electric vehicles
• harmonics suppression
• induction motors