基于电压突变量信息值的接地故障选相方法

Grounding Fault Phase Selection Method Based on Information Value of Voltage Sudden Change

为解决主动干预熄弧装置选相误判问题,研究了接地故障电压特征,针对不同接地电阻,分析故障前后电压量变化状况,计算电压突变量信息值形成选相序列,构建选相判别专家库,提出基于电压突变量信息值的接地故障选相方法,同时,根据合闸前后系统各线路零序有功分量变化特征实现装置选相校核,确保装置动作正确。该方法不受接地电阻大小影响,对各种接地故障具有较强适应性。利用Matlab进行建模和仿真,仿真结果验证了该方法的有效性。

To solve the problem of the active intervention type arc-extinguishing device can’t judge phase selection, this paper researches the characteristics of grounding fault voltage, the characteristics of voltage variation before and after fault are analyzed for different grounding resistance.The phase selection sequence is formed by calculating the information value of voltage mutation, which constructs the expert database of phase selection discrimination.It is proposed that the phase selection method of grounding fault based on voltage mutation information value.In addition, according to the changing characteristics of the zero-sequence active power component of each circuit before and after switching, phase selection check of the device is realized to ensure the correct action of the device. The method is not affected by grounding resistance and has strong adaptability to various grounding faults. Matlab is used for modeling and simulation, and the simulation results demonstrate the effectiveness of the method.