单相接地故障通常伴随电弧接地，电弧接地产生大量谐波，配电网非线性负载也会产生谐波，谐波直接导致故障零序电压、电流畸变，现有的信号分析方法不能准确的对故障畸变信号进行分解，直接影响现有故障选线方法的准确性。论文采用适用于畸变信号的数学分析方法计算分析含谐波的单相接地故障信号，可有效提高故障选线的可靠性，对保证配电网的安全运行具有重要意义。 论文研究了在畸变电压、电流作用下，利用Fryze非正弦分析方法分解畸变故障信号的优势。分别分析了中性点不接地运行方式下和中性点经消弧线圈接地运行方式下，故障线路和非故障线路等效电导与零序谐波电压频率、零序谐波电流畸变率等的影响关系，推导出当系统发生单相接地故障时，故障线路零序等效电导大于非故障线路零序等效电导的结论的结论。在此基础上，论文选用零序等效电导作为故障特征参数来辨识接地线路，在matlab仿真平台上编写并实现了单相接地故障选线算法。采用Fryze电流分解方法计算单相接地故障的零序等效电导时能够将谐波因素考虑在内，该方法不受中性点运行方式的影响，尤其适合于对单相弧光接地故障的辨识。 论文通过改变配电网不同的中性点接地方式、不同的线路参数、不同的谐波环境等条件，利用论文的选线方法对单相接地故障进行仿真分析，结果表明该选线方法均能准确选出故障线路，验证了论文选线方法的可靠性。

Single-phase ground fault is usually accompanied by arc grounding,which generates a large number of harmonics, which is also produced by distribution network nonlinear load. Harmonics have direct impact on fault zero-sequence voltage, current distortion,the accuracy of decomposition of fault distortion signal by the existing signal analysis method as well as the selection method of the existing fault line.The paper is to calculate and analyze the single-phase ground fault signal with harmonics by the mathematical analysis suitable for the distortion signal, which can effectively improve the reliability of fault line selection and plays a significant role in ensuring the safe operation of the distribution network. The paper is to decompose the characteristics of distorted fault signals by the method of Fryze non - sinusoidal analysis under the action of distortion voltage and distortion current. Based on non-grounded neutral point operation and grounded neutral point operation by arc suppression coil, the paper is to analyze the relations of fault line and non-fault line equivalent conductance with harmonic voltage frequency, harmonic voltage distortion rate and harmonic current distortion rate of the relationship.When the system brings about single-phase ground fault, the fault line zero-sequence equivalent conductance is greater than the non-fault one. On this basis, the paper takes zero-sequence equivalent conductance as fault characteristic parameter to identify the ground line and design the algorithm of the line selection and adopts matlab software to write the relevant procedures. The calculation of zero-sequence equivalent conductance of a single-phase-to-ground fault through the Fryze current decomposition method can take harmonic factor into account.The method is not affected by the operation of the neutral point, especially for the identification of single-phase arc grounding fault . By changes in the neutral point grounding method, different line parameters and harmonic environment of the distribution network and stimulating analysis on the single-phase ground fault by the method of line selection,the results show that the line selection method can accurately select the fault line without being affected by the above changes, which turns out the reliability of selection method in the paper.