我国配电网多采用中性点非有效接地运行方式，其发生单相接地故障时，故障电流微弱、电弧也不稳定，导致故障选线困难。本文研究了基于频域参数识别原理的配电网单相接地故障选线方法。 在建立单相接地故障的零序网络时，将线路等效为母线侧和负荷侧对地电容值不相等的集中参数π模型；根据频域参数识别的基本原理，在已知线路模型和参数的情况下，建立了线路发生外部故障时的频域参数模型，并利用最小二乘法对相关频域方程组进行求解。 考虑到基本矩阵束算法在信噪比低时计算精度不高，本文将奇异熵增量和矩阵束算法相结合，构成基于奇异熵定阶的矩阵束算法，利用该算法对故障信号的频点信息进行准确提取；再对比非故障条件下各类型线路的零序网络的相频特性以及故障条件下混合线路集中参数模型的相频特性来确定特征频带，并确定了线路在特征频带内的等效模型；通过选取特征频带内的频点信息来计算线路靠近负荷一侧的电容参数，并根据故障线路和健全线路在故障过程中等效模型是否发生变化这一性质，构造出暂态量信息与稳态量信息相结合的选线判据，实现对故障线路的准确选择。 通过ATP搭建了配电网辐射型供电网络，模拟架空线路、电缆线路和缆-线混合线路在不同网络结构、不同过渡电阻、不同故障位置和不同故障初相角条件下的单相接地故障，并利用MATLAB进行算法处理，验证本文基于频域参数识别的单相接地故障选线方法。仿真结果表明，本文所研究的选线方法是正确有效的，且具有较强的适应性和容错性。

Most of China's distribution network adopts neutral point non-effective grounding operation mode. When single-phase ground fault occurs, the fault current is weak and the arc is unstable, which makes the fault line selection difficult. In this paper, a single-phase ground fault line selection method based on frequency domain parameter identification principle is studied. When establishing a zero-sequence network with single-phase ground fault, the line is equivalent to a lumped-parameter π model with unequal capacitance values between the bus-side and load-side ground. According to the basic principle of frequency-domain parameter identification, in the case of knowing line models and parameters, the frequency domain parameter model of the external fault occurred on the line was established, and the related frequency domain equations were solved by the least squares method. Considering that the basic matrix pencil algorithm has low computational accuracy when the signal-to-noise ratio is low, this paper combines the singular entropy increment and the matrix pencil algorithm to form a matrix beam algorithm based on singular entropy to fix order, and using this algorithm to accurately extract the frequency information of the fault signal. Then, the phase-frequency characteristics of the zero-sequence network of each type of line under non-fault conditions and the phase-frequency characteristics of the mixed-line centralized parameter model under fault conditions are compared to determine the special frequency band, and the equivalent model of the line in the special frequency band is determined. By selecting the frequency point information in the special frequency band to calculate the capacitance parameter of the line near the load side, and the line selection criterion combining the transient information and the steady information is constructed according to the nature of whether the equivalent model changes during the fault process of the faulty line and the regular line, thereby achieving the accurate selection of faulty lines. Through the ATP, a radiation-type power supply network of the distribution network was built to simulate single-phase ground faults of overhead lines, cable lines and cable-line hybrid lines under different network structures, different transition resistances, different fault locations and different fault initial phase angle conditions. The data processing is carried out by using MATLAB to verify the single-phase ground fault line selection method based on frequency domain parameter identification. The simulation results show that the line selection method studied in this paper is correct and effective, and has strong adaptability and fault tolerance.