馈出线测量导纳互差求和法小电流接地选线研究

Study on the Earthed Fault Detection Method in Indirectly Earthed Power System Using Summation of Outgoing Feeder Measurement Admittance Mutual Difference

在分析小电流接地电网零序测量导纳分布的基础上,提出了一种新的小电流接地选线方法——馈出线测量导纳互差求和法。该方法有效地拉大了故障馈线与非故障馈线故障判断量的差距,极大地提高了保护裕度。由于该方法所用的故障判断信息大,使其抗干扰能力大为增大。仿真和初步运行情况证明,该方法有效地提高了小电流接地选线的准确性。

On the basis of detailed analysis of the zero sequence measurement admittance distribution in the indirectly earthed power system, a new fault detecting method of summation of the outgoing feeder measurement admittance mutual difference is proposed. This method has effectively increased the difference of the fault judging quantity in fault feeder and non-fault feeders, and the protecting abundant degree has been also greatly enhanced. The anti-interference capability of this method can be greatly increased because the method uses a great amount of the fault judging information. The simulation and operation results indicate that this method is effective.