小波分析在PWM整流器去噪中的研究

Research on noise reduction of PWM rectifier with wavelet analysis theory

为了减少大功率PWM整流器中采集到的固有噪声信号的影响,提高其变流控制的精度,将小波分析理论引入到PWM整流领域。并利用db小波对PWM整流器交流侧的电流反馈信号进行了多层小波分解,把反馈的电流信号分解为多个层次的高频部分和低频部分,最后按实际需求对信号进行重构达到降噪的目的。实验结果表明,小波分析方法的应用能有效地消除PWM整流器中的噪声干扰,在机车变流器的信号降噪处理方面有广阔的应用前景。

In order to reduce the impact of inherent noise signal on high-power PWM rectifier and enhance the control precision of the converter, the wavelet analysis theory was introduced to PWM rectifier fields. The noise is generally contained in high frequency coefficients. The authors have carried on mulfilayered wavelet decomposition using the db wavelet to the current signal of the PWM rectifier exchange side. By decomposing the current signal into many levels including the high frequency part and the low frequency part, the signal reconstruction can eventually achieve the purpose of noise reduction. The experimental results indicated that the application of wavelet analysis methods can effectively eliminate noise in PWM rectifier and it has broad application prospects in locomotive signal processing.