基於故障相電壓功率譜的串補輸電線路故障識別

FAULT RECOGNITION FOR EHV/UHV TRANSMISSION LINEWITH SERIES CAPACITORS BASED ONPOWER SPECTRUM OF FAULTY PHASE VOLTAGE

超高壓串補輸電線路在單相暫態性接地故障時，故障相恢復電壓包含工頻分量、接近於工頻的分量以及低頻分量，其功率譜有3條譜線；而永久性接地故障時，故障相恢復電壓僅由工頻分量、低頻分量疊加而成，其功率譜有2條譜線。據此針對串補輸電線路提出一種基於故障相恢復電壓功率譜的單相接地故障識別方法，該方法利用故障相電壓各分量功率譜的譜線分佈來識別暫態性故障和永久性故障，EMTP模擬驗證了該方法的準確性和可行性。

The recovery voltage of the fault phase during occurrences of singlephasetemporary faults in EHV/UHV transmission lines with series capacitorsis composed of the components of power frequency, approximate power frequency,and low frequency. The power spectrum of the recovery voltagepossesses three spectral lines. However, the recovery voltage of singlephasepermanent fault only contains power frequency and low frequencycomponents, and its power spectrum possesses two spectral lines. On this basis, an identification method of temporary and permanent single-phaseearth fault was proposed for the transmission lines with series capacitors.Simulation results showed that the proposed method based on power spectrumof fault phase recovery voltage was accurate and feasible.