基于暂态零序电流偏度特征的小电流接地系统单相接地故障区段定位

Location of Single Phase to Ground Fault Section in Small Current Grounding System Based on the Characteristics of Transient Zero Sequence Current Skewness

国内中压配电网中性点主要采用不直接接地方式,由于单相接地故障信号微弱并且越来越多的外界条件干扰等原因,故障区段定位未得到有效解决.单相接地故障发生时,故障区段两侧检测装置暂态零序电流极性相反,健全区段两侧检测装置暂态零序电流极性相同.基于此特征,文中提出一种利用暂态零序电流数据分布的偏度(Skewness)特征判定故障区段.该方法根据故障区段两侧检测点的偏度值极性相反,实现故障区段定位.通过仿真模拟验证所提方法的有效性.

The neutral point of distribution network in China is not directly grounded.Because of the weak signal of single-phase grounding fault and more and more interference of external conditions,the location of fault section has not been effectively solved.When a single-phase ground fault occurs,the polarity of the transient zero sequence current of the detection devices on both sides of the fault section is opposite,and the polarity of the transient zero sequence current of the detection devices on both sides of the healthy section is the same.Based on this feature,a new fault section detection method is proposed,which uses the skewness feature of transient zero sequence current data distribution.According to the opposite polarity of the detection points on both sides of the fault section,the method can locate the fault section.The effectiveness of the proposed method is verified by simulation.