Study on Active Suppression of Noise Under Wide Frequency Domain of PMSM

At present, in the traditional research field of motor harmonic current suppression strategy, most of the research mainly focuses on low-order or high-order harmonic currents, and there is a lack of research on harmonic currents suppression over the wide frequency range, which leads to the inability to effectively suppress the vibration noise of the motor over the wide frequency range in the process of practical application. Therefore, this paper proposes a hybrid control strategy, which combines harmonic injection, random zero-vector distribution and random switching frequency (HJ-RZDSF).

First, a control strategy (RZDSF) with optimal switching frequency variation range is used to suppress high-order harmonic currents. In response to the fact that the RZDSF leads to an increase in the amplitude of the low-order harmonic currents, we jointly employ a harmonic injection control strategy (HJ), which results in vibration and noise suppression over a wide frequency range of the motor.

Comparedwith the traditional control strategy, the noise level at low frequency is reduced by 88% on average and the noise at high frequency is reduced by 78.5% on average.

Finally, the three-phase current signals and noise signals of the motor under load conditions were collected by current sensors and sound intensity sensors. The experiment verifies that the control strategy proposed in this paper can effectively attenuate the low-order harmonic currents and high-order harmonic currents of the motor and reduce the motor noise in a wide frequency domain.