研究了故障行波的频谱与故障距离以及线路终端的系统条件3者的关系,特别是线路终端的系统等效阻抗对行波频谱的影响。在此基础上,提出了频域的单端行波故障测距方法。首先提取故障行波的频率主成分,确定在此单一频率下的波速、系统端和故障点反射角,然后计算出故障距离。分析了单相高阻接地故障时行波频谱的特点及算法的误差。用不同故障距离和故障类型的仿真算例对算法的精度进行了验证。
The relationship between the spectrum of traveling waves, the fault distance and the terminal conditions of transmission lines is discussed. Especially the effects of the system equivalent impedance to the traveling wave spectrum are studied. A novel frequency domain approach to the single-ended traveling wave fault location is presented based on the study. Firstly the dominant component of the traveling wave natural frequency is extracted. Then the propagating velocity, the reflection angles at the line end and fault point at this particular frequency are determined. Finally the fault distance can be derived. The feature of the high resistance single-phase to ground fault traveling wave spectruum is presented and the error of the algorithm is analyzed. The accuracy of the algorithm is verified by simulation cases of varied fault distances and fault types.