输电线路受绝缘子闪络、雷击、山火等因素易发生弧光高阻接地故障,电弧的动态非线性和高阻性直接导致了单端阻抗测距精度的下降。常规基于热平衡原理的动态电弧模型均为实时迭代计算的微分方程,无法直接与现有阻抗法故障测距算法相结合。针对该问题,该文基于输电线路弧光高阻接地故障主要为大气压短间隙放电的现实,提出了基于汤逊原理的高阻接地电弧对数模型及故障测距算法,仿真分析不同故障及系统运行状况下的算法精度,现场录波数据证实了所提算法的有效性。
Arc high-impedance grounding faults are frequently occurred in transmission lines with different fault reasons, such as insulator flashover, lightning or fire. The nonlinear and high impedance characteristics of arc produce directly the poor performance of single-end fault location algorithm in line. Traditional dynamic arc models are mostly based on the principle of heat balance, and it is usually expressed with real time iterative computation of differential equations, hence it cannot be directly adopted in the impedance based fault location algorithm. In response to this question, based on the fact that air discharging of transmission line mostly occurs in the condition of short gap under normal air pressure, a novel dynamic arc model and corresponding fault location algorithm were proposed based on the Thompson theory in this paper. The accuracy of the novel algorithm was tested with different power system operation status and real recorded data in field.