基于阻抗法的电力电缆高阻故障定位理论及试验

电力电缆的高阻故障的准确定位是一个比较困难的课题。本提出了基于阻抗法的变频电力电缆故障定位方法。该方法采胜频率比工频高的正弦电源，仅仅采集故障状态下故障相电缆单端的电压、电流信号。其原理是：电弧是电阻性的，因此流过故障点的电流和故障点两端的电压是同相位的，采集到线路首端的电流和故障点两端的电压是同相位的，采集到线路首端的电压与电流后，基于分布参数线路理论就可以求出沿线路各点的电压与电流，在故障点处电压与电流是同相位的。本正是利用这一点推导出故障定位方程。经过数字仿真试验和低压模拟实验证明，该方法是可行的，具有较高的定位精度。

ON-LINE DISTRIBUTED FAULT SECTION ESTIMATIONSYSTEM WITH RADIAL BASIS FUNCTION NEURAL NETWORK

The accurate location of power cable fault under high resistance is rather difficult. In this paper a power cable fault location method based on impedance and using frequency variable power source is put forward. In this method a high voltage ac power source with sinusoidal waveform and frequency higher than 50Hz is applied to the receiving end of faulty cable to make the faulty position flashed. Only collecting the voltage and current signals at the receiving end of faulty phase under this condition, then by use of deduced fault location equation the faulty position can be determined. The reason of this method lies in that: because the arc is resistive, so the phase angle of the current flowing through the cable will be equal to the phase angle of the voltage at any position in the cable, thus, after the voltage and current signal at the receiving ends are collected the fault location equation can be deduced according the theory of transmission line with distributed parameters. The results of simulation by EMTP and low voltage simulation experiment show that this method is feasible and its locating accuracy is satisfactory.