Simulation on Grounding Fault Location of Distribution Network Based on Regional Parameters

The distribution network fault will cause big range and long-time blackout which will affect the safe and stable operation of the power system. The difficulty of locating grounding faults in power distribution networks is arc-suppression-coil-ground neutral system. The introduction of the arc suppression coil and the increase of the compensation current in the system make the relationship among zero sequence currents more complex, moreover, the comparison of zero sequence currents to realize the grounding fault location of arc suppression coil becomes more difficult. Although the residual increment method, short-circuit fault indicator method, signal injection method and first-half wave method are proposed in our country, but their effect are not good for grounding fault with high transition resistance, and the success rate of the grounding fault location is not high. In order to improve the real-time and accuracy of online monitoring for grounding fault location in the distribution network, this paper proposes a grounding fault location method based on regional parameters. The method divides the distribution network into several regions, and each region is installed a zero-phase sequence current transformer at the boundary. The transformer is used to measure the zero-phase sequence current, and the voltage transformer is used to measure the three-phase grounding voltages. According to the zero-phase sequence current, it can calculate the total grounding current of each region; through analysis and calculation of the total grounding current and the grounding voltages of three-phase line, we can get the three-phase grounding conductivities and the three-phase grounding susceptances. The simulation verifies that the grounding fault diagnosis method based on regional parameters has certain versatility, especially for high resistance grounding fault problems, thus it has great significance to ensure the safe and stable operation of distribution network and transmission line. Keywords—high power grid; grounding faults; regional parameters