基于零序电压调控的故障选线选相新方法

A new method of fault line selection and phase selection based on zero sequence voltage regulation

为解决配网高阻接地故障选线与选相准确率较低的问题,提出了一种基于零序电压调控的接地故障选线与选相新方法。通过分析零序电压调控前后各馈线零序电流的相角特征,根据健全线路与故障线路零序电流前后相角差值的绝对值存在明显区别选取故障线路。在完成故障馈线辨识的基础上,利用零序电压调控前后故障线路的零序电流完成故障选相函数的相角值计算,故障选相函数值较小者所对应的相别即为故障相。仿真分析表明,所提方法不仅将选线与选相方法有效结合,而且调节系数灵活多变,适用于不同运行方式下的低、高阻接地故障。

In order to solve the problem of low accuracy of line selection and phase selection when a high resistance grounding fault occurs in a distribution network system, a new method of line selection and phase selection for a grounding fault based on zero-sequence voltage regulation is proposed. By analyzing the phase characteristics of the zero-sequence current of each feeder before and after the zero-sequence voltage regulation, the fault line can be selected according to the obviously different absolute value of zero sequence current phase difference between the healthy line and the fault line. On the basis of completing the fault feeder identification, the phase values of fault phase selection function are calculated using the zero-sequence current of the fault line before and after zero-sequence voltage regulation, and finally the phase corresponding to the smallest fault phase selection function value is the fault phase. The simulation analysis shows that the proposed method not only effectively combines line selection with the phase selection method, but it is also suitable for low and high resistance grounding faults operated in different ways through a flexible adjustment coefficient.