Line Parameter Estimation of Distribution Network after Grounding Fault

With the high impedance single-phase ground fault occurs in a distribution network, the line parameters will change substantially. Typically, the neutral resonance grounding is used to compensate the fault current. Better results can be achieved with active compensation, but precise line parameters need to be known. In this paper, an existing method of estimating distribution line parameters using only RMS voltage and power measurements is employed to estimate distribution line parameters after high impedance single-phase ground fault. The power flow equation without voltage phase angle, the compensation model of active compensation device and the measurement error compensation model are established. Simulation results obtain the required line parameters while reducing measurement error and computational complexity. It is conducive to the subsequent state analysis of distribution lines.

I. Introduction

The distribution network covers a wide range of areas, and its operating environment is very complex, which makes the distribution network prone to single-phase ground fault [1] . After the ground fault occurs, the parameters of distribution lines vary significantly due to the different conditions of the environment and fault materials. It is necessary to analyze the distribution line parameters in various states in detail to study their impact on the system. Accurate grid topology and line parameters are the critical components of the grid system model, which are essential to the operation and planning of the power system [2] . In this case, state estimation (SE) of distribution networks with ground faults through existing grid data becomes the key to obtain accurate information on distribution network operation [4] . At the same time, the practicability of parameter estimation largely depends on the accuracy of the power network model and parameter calculation [5] . In the existing methods of parameter estimation of distribution network, transient analysis is often used to estimate the state of the line when a ground fault occurs.