CAJ | 학술논문

线路发生接地故障时,两侧零序阻抗相差过大将导致两侧零序电流差别过大,虽然两侧的零序方向元件均能正确动作,但是由于一侧零序电流达不到动作定值,从而造成纵联零序方向保护拒动.文中针对这种零序弱馈现象的产生进行了仿真分析,并且提出了针对零序弱馈的纵联零序方向保护的改进方案,进行了验证.实时数字仿真试验结果表明该方案解决了零序弱馈时的纵联零序保护拒动问题,有效改善了纵联接地保护的性能.
선로발생접지고장시,량측령서조항상차과대장도치량측령서전류차별과대,수연량측적령서방향원건균능정학동작,단시유우일측령서전류체불도동작정치,종이조성종련령서방향보호거동.문중침대저충령서약궤현상적산생진행료방진분석,병차제출료침대령서약궤적종련령서방향보호적개진방안,진행료험증.실시수자방진시험결과표명해방안해결료령서약궤시적종련령서보호거동문제,유효개선료종련접지보호적성능.
When ground faults occur on transmission lines, zero sequence currents of both ends will be very different from each other if there is a significant difference between the zero sequence impedance of both ends. Pilot zero sequence directional protection may fail to operate because the zero sequence current on one end does not reach the set value of the protective relay,although zero sequence directional elements on both ends operate correctly. This paper performs a simulation analysis on the phenomenon of zero sequence weak-infeed and an improved scheme of pilot zero sequence directional protection is proposed to address this problem. The result of real-time digital simulation demonstrates that the improved scheme can handle the miss operation problem due to the phenomenon of zero sequence weak-infeed and effectively improve the performance of pilot ground fault protection.