信号源激励法在判断线路是否挂接地线中的应用

Application of Signal Source Excitation in Determining Whether Any Ground-wire Is Linked to the Power Line

为避免带地线合闸送电事故,提出了在信号源激励下对采样点响应信号进行快速傅里叶变换(FFT),分析响应信号的频谱特征来判断线路有无临时地线的新方法。分别对直流、正弦波、方波、三角波激励下响应的幅频特性进行了分析,结果表明,响应信号的幅频特性与当前线路是否接地密切相关,并且直流激励下响应信号的特点更明显。此方法可以用来判断线路是否挂接地线,为避免带地线合闸送电事故提供了强有力的技术手段。

To avoid the accident caused by closing the breaker when ground-wire is still on, a new method for the iden- tification work of ground-wire is put forward in the paper. In this way, a signal source is needed and the response sig- nal of sampling points is processed through the method named Fast Fourier Transform （FFT）, then analysis of the spectrum characteristics of the response signal will help determining whether ground-wire is still on. The response sig- nal of DC source, sine wave, square wave, triangle wave are all analyzed and the result shows the amplitude-frequen- cy characteristics of response signal are closely related to whether any ground-wire is still on and the characteristics of DC source are more obvious. This method can be used to determine whether any ground-wire is stitl hung on the power line, providing a powerful technical means to avoid the accident caused by closing the breaker when ground-wire is still on.