一种减小无刷直流电动机噪声的PWM调制方法

A PWM Modulation Method to Decrease Noise of Brushless DC Motors

提出一种三相绕组同时参与调制的方法,以减小无刷直流电动机换相期间的转矩脉动和噪声。该方法包括三种调制方式,分别计算了每种方式关断相、开通相以及非换相相占空比的数学表达式。以1台5.5 k W无刷直流电动机为例,通过瞬态声场有限元仿真,证明采用该方法能有效抑制电动机噪声。最后对该台样机不同PWM调制方法的转矩脉动和噪声进行测试,验证了所提方法的正确性和可行性。

In the paper, the three-phase corporative modulation method is proposed for suppressing brushless DC motors commutation torque ripple and electromagnetic noise. In this method,there are three types of modulation. The duty cycle expressions of the off-going phase,the on-going phase,and the non-commutation phase are calculated. The finite element method is adopted to analyze transient acoustic field of one 5. 5 k W. The proposed method is illustrated to be suitable to suppress electromagnetic noise. The torque ripple and electromagnetic noise with different PWM modulation method for the 5. 5 k W prototype motor is built for test. The validity of the proposed method is confirmed by both simulation and experimental results.