Abstract:
When the frequency converter adopts the space vector pulse width modulation (SVPWM) control strategy to modulate, there is a large amplitude harmonic current near the switching frequency and its double frequency, which will produce high-frequency electromagnetic noise with greater harm. To solve this problem, an improved random switching frequency SVPWM control strategy is proposed to suppress the high-frequency electromagnetic noise of the motor. Firstly, a random switching frequency SVPWM control strategy is designed based on logically mapped chaotic sequences; secondly, on the basis of random switching frequency SVPWM, the control strategy is improved by adding multi-random cycle numbers and specific carrier frequency segment limitation technology; finally, the multi-physics coupling method is used to verify the improved random switching frequency SVPWM control strategy. The results show that compared with the traditional SVPWM control strategy, the improved random switching frequency SVPWM control strategy has a significant effect on reducing the high-frequency electromagnetic noise near the switching frequency of the motor, and the average sound pressure level is reduced by 2.53 dB.