单相接地非故障相母线电压差异的案例分析

Case Study on Voltage Difference of Single-phase Grounded Non-fault Phase Bus

通过两起110kV线路单相接地故障的录波,对比并计算分析得出,负荷侧中性点不接地时,负荷侧非故障相母线电压仅与故障点靠电源侧的Z0与Z1的相对大小有关;负荷侧中性点接地时,负荷侧非故障相母线电压的变化不仅与两侧的综合正负零序阻抗大小相关,还与N侧背后的零序阻抗ZNS0和K点靠N侧的综合零序阻抗ZN0之比有关。

By comparing the recording of two single-phase ground faults of 110kV line and calculating and analyzing,it is concluded that when the load-side neutral point is not grounded,the non-fault phase bus voltage on the load side is only related to the relative magnitude of Z0and Z1on the power supply side of the fault point;when the load-side neutral point is grounded,the change of the non-fault phase bus voltage on the load side is not only related to the combined positive and negative zero-sequence impedances on both sides,but also to the ratio of the zero-sequence impedance ZNS0on the N side to the combined zero-sequence impedance ZN0on the N side of Kpoint.