同杆并架输电线路跨线故障识别元件

通过对线路发生单纯性故障与跨线故障情况下的正、负序故障分量阻抗关系和正、负序故障分量电流幅值关系的分析，提出了一种判别电力系统发生跨线故障的判别元件。单纯性故障时，正负序阻抗角相等、正负序阻抗幅值相等、正序故障分量电流幅值不小于负序电流幅值；而当发生跨线故障时，以上关系不再成立，由此便可以得到系统发生跨线故障的判据。该判别元件原理简单，动作灵敏度高，EMTP仿真和现场录波数据验证了该判别原理的准确性。

Cross Country Fault Identifier for Power System Transmission Line on a Same Pole

Based on the analysis on the relationship of the positive and the negative sequence impedance, also the positive and negative fault component current under simple and duplicate fault conditions, a cross-country fault identifier is proposed. Under the circumstance of simple fault on double circuit transmission lines, the positive-sequence impedance is equal to the negative-sequence impedance, and the positive fault component current is equal to or greater than the negative circuit. But the relationships above do not exist under the duplicate fault. Based on this criterion, the cross-country fault identifier is designed. EMTP simulations and fieldwork data test results show that the cross-country fault identifier is correct and reliable.