Research On Tuning Related Problems Of Resonant Grounding Power System

In China’s medium-voltage distribution network,the resonant grounding method has gradually become a more and more popular neutral grounding because of its better power supply reliability and safety.However,along with the rapid development of urbanization and the increase of the degree of line cable,the capacitance of the system to the earth is getting larger and larger.The resonant grounding system faces the problems of insufficient compensation capacity of arc suppression coil,difficult tuning and low alignment accuracy.Therefore,it is necessary to study the tuning related problems of resonant grounding power system.This paper first introduces the development of distribution network neutral grounding at home and abroad,elaborates the development of resonant grounding system and some problems encountered,and analyzes the grounding principle and operational characteristics of resonant grounding.In this paper,Grounding system tuning related issues lay the theoretical foundation.Secondly,the existing tuning methods of arc suppression coil are studied,the characteristics of the existing tuning methods and their applicable scope are analyzed,and a system ground capacitance current measurement method based on preferential ground fault line selection is proposed.At the same time,aiming at the insufficiency of compensating capacity of arc suppression coil,a scheme of dispersion compensation of arc suppression coil is proposed.The basic principle of dispersion compensation and dispersion compensation arc suppression coil device is analyzed.The analysis of ground residual current and arc overvoltage.The compensation effect and arc extinguishing performance of arc suppression coil in single-phase-to-ground fault are studied.The rationality and feasibility of decentralized compensation scheme of arc suppression coil are verified by MATLAB simulation results and actual conditions.Finally,the neutral point arc suppression coil grounding system of the problem of selecting the line has been studied.This paper analyzes the current situation of the line selection of resonant grounding system,and then takes the cooperation of arc suppression coil tuning and line selection as an opportunity,proposes a line selection method based on eigenvalues of zero sequence current changes and a single phase grounding Line selection of new methods.MATLAB simulation results show that these two kinds of single-phase ground fault line selection method has a certain feasibility and effectiveness,and has certain engineering value.