基于微量法的发变电站接地网腐蚀故障诊断

Corrosion Fault Diagnosis for Power Station and Substation's Grounding Grid Based on Micro Method

腐蚀故障的出现会使接地网的可靠性降低。介绍了接地网腐蚀故障诊断的基本思路和方法,构造了基于特勒根定理的腐蚀故障诊断方程,并采用双激励源和多电流值输出的方法增加方程中独立方程的个数。针对腐蚀前后支路电阻值变化很大和方程的非线性问题,采用微量线性处理法和迭代计算进行处理,同时使用端口电压测量值确保迭代逼近的正确方向。针对一个接地网仿真模型进行模拟故障诊断,结果表明,该方法能准确判断故障支路位置,且可大概估计腐蚀后故障支路的电阻变化倍数。

The appearing corrosion faults will lower the reliability of grounding grid.Introduction was made to the basic idea and method of corrosion fault diagnosis for grounding grid.This paper constructed the corrosion fault diagnosis equation based on Tellegen's theorem and adopted the dual-excitation source and multi-current value output method to increase the independent equation numbers in equations.In allusion to the problems that the circuit branch resistance value fluctuated greatly before and after corrosions,as well as the nonlinearity problem,the iterative algorithm based on micro linear processing was adopted and the port voltage observed value was used to guarantee the right direction toward the iteration.A model of grounding grid was carried out the simulated fault diagnosis.The results show that this method can judge the fault circuit branch's position accurately,to roughly estimate the resistance variation multiple of corrosion fault circuit branches.