我国中压配电网的中性点广泛采用经消弧线圈接地的运行方式。在系统发生单相接地故障后，由于消弧线圈的补偿作用，使得故障电流微弱，同时由于电弧不稳定，故障情况复杂等原因，导致谐振接地系统故障选线问题一直未能得到很好解决。利用故障稳态分量进行故障检测，存在的主要问题是稳态分量小，检测难度大。与故障稳态分量相比，故障暂态分量具有幅值大，不受消弧线圈影响，故障检测灵敏度高等优点。因此，本文从研究暂态过程特征着手，探索基于暂态量的故障选线新方法。 针对谐振接地系统单相接地故障暂态过程特征机理不甚明确的问题，在考虑接地电阻的情况下，分析单相接地故障特性，利用电路动态方程得到了单相接地暂态电流与故障时刻、接地电阻等的函数关系式，从根本上揭示了谐振接地电网发生单相接地故障的暂态机理。 在分析暂态规律特性的基础上，从能量角度出发，将经验模态分解与能量相结合，定义固有模态能量、能量权重系数和相对能量因子作为故障特征参数，实现对故障暂态量信息的数据挖掘。提出基于固有模态能量的暂态量选线方法，求取故障后各条线路的暂态零序电流的固有模态能量，计算各条线路的能量权重系数与相对能量因子，通过比较各条线路相对能量因子辨识故障线路。通过改变消弧线圈的补偿度、在故障零序电流中混入噪声、在系统中注入谐波分量、改变线路结构进行仿真分析，验证了该选线方法在谐振接地系统单相接地故障中具有良好的可靠性能。 分别建立了架空线路、电缆线路、缆线混合线路三种谐振接地系统模型，在不同故障条件下，对选线方法进行分析验证。利用10kV高压模拟系统的实验室录波数据验证选线方法的性能。结果表明，基于固有模态能量的暂态量选线方法能够正确可靠的实现谐振接地系统故障选线。

In our country, arc-suppression coil is widely used in neutral point grounding in medium voltage distribution network. When the single-phase-to-ground fault has occurred, the fault current is weak because of the compensation effect of arc suppression coil, meanwhile, the arc is unstable and fault conditions is so complicated that the fault line selection hasn’t been solved well in resonant grounded system. The main problem of using fault steady-state components to fault detection is that the steady-state components are too small to detect. Compared with the fault steady-state components, the fault transient components have some advantages, such as large amplitude, non-influenced by arc suppression coil and high sensitivity, etc. Therefore, the characteristics of transient process are studied for the sake of exploring new method of fault line selection. In view of the single-phase-to-ground fault transient process characteristics mechanism in resonant grounded system are unclear, considering the grounding resistance, the characteristics of single-phase-to-ground fault are analyzed. The functions between the transient current and fault time as well as grounding resistance are analyzed according to dynamic circuit, so as to reveal the single-phase-to-ground fault transient process characteristics mechanism in resonant grounded system fundamentally. On the basis the analysis of the transient characteristics, from the view of energy, the empirical mode decomposition is combined with energy, and the intrinsic mode energy, energy weight coefficients and relative energy factors are defined as fault characteristic parameters, so as to pick fault transient information. The fault line selection method based on intrinsic mode energy is proposed, the intrinsic mode energy of zero sequence transient current of each line are fetched after the fault has occurred, the energy weight coefficients and relative energy factors of each line are calculated, the relative energy factors of each line are compared to realize fault line selection. After simulating by changing compensation degree of arc-suppression coil, mixing the zero-sequence current with noise, injecting harmonics component into system, and changing the line structure, the proposed fault line selection method has been verified reliable for single-phase-to-ground fault in resonant grounding system. Three kinds of resonant grounding system model (overhead lines, cable lines, hybrid transmission lines) are established, the new method is analyzed and verified under different fault conditions. Besides, its performance has been proved according to the recorded data from 10kV high voltage physical experimental system. The study has shown that the fault line selection method based on the intrinsic mode energy can achieve fault line selection in resonant grounding system accurately and reliably.