超高压同杆双回线中性点小电抗的精确计算方法

Accurate Calculation Method for Neutral Reactor of EHV Double-Circuit Line

为解决带并联电抗器和中性点电抗器的同杆双回长线路单相接地故障后的非全相运行潜供电流和恢复电压精确计算问题,采用特征模量分解法对同杆多回线间的零序参数解耦,提出基于同杆双回线实测参数(正/负序阻抗和电纳及零序的自阻抗、互阻抗、自电纳和互电纳)的同杆双回长线路非全相运行公式。结果显示,利用该公式计算的故障点潜供电流和恢复电压,为同杆双回线中性点电抗器的参数确定提供了可靠依据,具有一定的工程应用价值。

To solve the accurate calculation problem of secondary arc current and recovery voltage in non-complete-phase operation after single-phase grounding fault of double-circuit line with shunt reactor and neutral reactor,this paper used eigen-model decomposition method to decouple zero sequence parameter in double-circuit line,and proposed the formula for non-complete-phase operation of double-circuit line based on its measured parameters：positive/negative sequence impedance,electrical susceptance,zero sequence self-impedance and mutual impedance,zero sequence self-susceptance and mutual susceptance.The results show that the calculation result of secondary arc current and recovery voltage at fault point can provide a reliable basis for the parameter determination of neutral reactor in double-circuit line,which is valuable to engineering application.