基于HHT小电流接地电力电缆在线故障测距方法

使用电力电缆进行电力传输已经逐渐被推广,在小电流接地系统发生单相接地故障时,系统可以带故障运行1~2小时,在此期间,需要检测出故障的位置。文章提出一种基于HHT小电流接地系统电力电缆单端在线故障测距的方法,在电缆参数未知的情况下,采用合闸的方法在线测量行波波速,单相接地故障发生后,利用HHT寻找行波瞬时频率突变的时刻,并运用单端测距法实现电力电缆故障测距。最后,对算例进行数值仿真,仿真结果验证了该方法的可行性和实用性。

A Method of Power Cable Fault Location Online in Neutral Point Ineffectively Grounded Power System Based on HHT

Power cable for power transmission has been gradually extended. The system can be still running 1-2 hours when single-phase-to-earth fault occurs, which requires the location of the fault is detected in the case of UPS. A method of power cable fault location online in neutral point ineffectively grounded power system based on HHT is proposed in this paper. Under the condition that the parameters of cable are unknown, the velocity of traveling wave in cable can be measured by the use of switching overvoltage wave which is generated when the closing occurs. When single-phase-to-earth fault happens, HHT is used to find the mutations moments of instantaneous frequency. Then the location of power cable fault is determined by one-terminal fault location method. Finally, the digital simulation results of an example show the effectiveness and practicability of this method.