基于小波变换的直流系统接地故障检测

直流系统接地故障检测常用的低频信号注入法容易受到支路电缆对地电容的影响。这里引入小波变换检测法,通过选取适当的小波函数,可以有效地克服对地电容的影响。在检测直流接地故障时,利用小波变换算法从检测到低频电流中提取出与注入信号同频的低频电流,通过计算该电流信号中的阻性分量,求得该支路的接地电阻值,可以判断出接地支路。MATLAB仿真分析,证明这种方法可在对地电容影响下,能正确判断出故障支路。

DC System Grounding Fault Detection Based on Wavelet Transform

The method of low frequency signal injection, which is usually used to detect DC system grounding tault, is easily influenced by the distributing ground capacitance. Here an advanced method based on wavelet transforms is introduced. Depending on selecting the suitable complex wavelet function, it can eliminate the influence of distributing ground capacitance efficiently. MATLAB simulation has proven that this method can distingish the faulty branch of DC system accurately without affecting by the ground distributing capacitance.