概率密度函数对RPWM逆变器的影响

The Effects of PDF on the Random PWM Inverters

PWM逆变器工作于人耳可听频率范围时会产生环境污染——声学噪声。随机PWM技术是降低声学噪声的经济、有效方法。随机开关频率PWM技术是噪声抑制效果最好的一种随机PWM方法,而有限个开关频率点的PWM技术是易于实现的,并且可用于闭环控制。基于此,首先讨论了如何对有限个频率点进行优化设计;其次,对有限个频率点的不同概率密度函数(Probability Desity Function,简称PDF)对逆变器输出电压和噪声的影响进行了对比分析。

Acoustic noise is a drawback of PWM inverters switching at frequencies within the audible range.Random PWM （RPWM） techniques are economical ahematives for acoustic noise reduction.Random switching frequency method has the best effect.By considering of the realization and the using of closed-loop control,the number of switching frequencies must be limited.To this end,this paper firstly discusses how to optimize the limited pool frequencies,and then, compares the impact that different well-know PDFs assigned to the switching frequencies in the limited pool upon the output voltage waveform and acoustic noise.