小电流接地系统发生接地故障时，利用prony算法提取暂态特征分量并利用相关分析法实现选线取得很好的效果，有效的排除了干扰信号的影响，结论明显、准确性高。-When the small current grounding system occurs ground fault , we use prony algorithm to extract the transient characteristics of the component and line selection by using co