Hybrid Carrier Frequency Modulation Based on Rotor Position to Reduce Sideband Vibro-Acoustics in PMSM Used by Electric Vehicles

Abstract

In the permanent magnet synchronous motor (PMSM) drive system, the unwilling and ear-piercing vibro-acoustics caused by high-frequency sideband harmonics becomes unacceptable in electric vehicle applications. In this paper, a modified space vector pulse width modulation (SVPWM) technique implemented with a hybrid carrier frequency modulation (HCFM) is provided to reduce the sideband current harmonic components and vibro-acoustic responses. The principle and implementation of the proposed HCFM technique are firstly presented in which the fixed carrier frequency is improved with the sawtooth and random signal-based coupling modulation based on the rotor position. The analytical derivations with the power spectral density method are also proposed. For verification, the experiment tests are conducted on a prototype 12/10 PMSM and microcontroller unit. The effectiveness of the HCFM technique can hence be confirmed considering the sideband vibro-acoustics reduction operated more effectively than that in a conventional random PWM. The proposed approach may provide a new route in noise-cancelling and electromagnetic compatibility for the electric drive powertrain.