【摘要】 局部放电是导致变频电机绝缘过早破坏的主要原因之一。由于PWM脉冲电压频率高、上升沿陡,含有较多的谐波分量,使传感器耦合出来的信号包含了很多干扰,导致局部放电信号的分析比工频正弦条件下更加困难。本文提出了采用sym4小波分析法去除高频噪声,能有效地提取这种条件下的局部放电信号,为进一步分析绝缘破坏机理打下了良好的基础。更多还原

【Abstract】 Partial discharge (PD) is one of key factors which lead to premature failure of inverter-fed motors. Pulse-width modulation (PWM) pulses have fast rise-time, high frequency and many harmonic components which may be coupled as interference by PD sensor. Thus it is more difficult to extract PD signal under PWM condition than sinusoidal wave condition. In this paper, a new sym4 wavelet digital filter is introduced. High-frequency noises are removed by wavelet analysis. PD signal is extracted effectively with this new compounded filter.更多还原