对由同杆四回线与同杆双回线构成的T型同杆四回线的故障选线进行了研究,提出一种先判断故障侧并识别故障侧支路的故障选线方法。首先对同杆四回线电路部分进行解耦,分别得到两端的反序电流之间的关系。基于此电流关系判断出故障侧,从而可以迅速确定故障发生的区域。在此基础上,引入正序电压差参数,实现对故障线路的进一步的选线。理论分析及EMTP仿真验证了所提方法的正确性,且选线精度高。
Teed circuits with four-parallel lines on the same tower consist of four-parallel lines on the same tower and quadruple-lines on the same tower. After analyzing the fault line selection, a new method is proposed. The fault region is determined at first, and then the specific fault branch is identified. The mutual electromagnetic effect between four-parallel transmission lines is decoupled to obtain the relationship between the inverted-sequence current of two power source sides. According to that, the fault side is identified and the fault area can be determined quickly. The positive-sequence voltage difference is introduced to detect the fault branch precisely. Both a theoretical analysis and EMTP simulation results show that the method is correct and has high precision.