Influence of periodic carrier frequency modulation on low frequency electromagnetic interference of permanent magnet synchronous motor drive system

This paper introduces periodic carrier frequency modulation (PCFM) to permanent magnet synchronous motor (PMSM) drive system to improve the electromagnetic compatibility. PCFM is introduced to reduce low frequency CM conducted EMI of PMSM drive system. Simulations and experimental results verify that sinusoidal and sawtooth PCFM can reduce CM conducted EMI of PMSM drive system effectively. Furthermore, sawtooth PCFM is more effective than sinusoidal PCFM in suppressing CM conducted EMI of PMSM drive system. Moreover, the reduction about CM conducted EMI of PMSM drive system by sinusoidal and sawtooth PCFM improves with the increase of spreading frequency widths.