Research On Resonant Grounding System Line Selection Based On Variational Mode Decomposition

With the development of modern society,the continuous improvement of people’s power consumption level,it becomes more and more important to maintain the security and stability of the power system.Most of China’s power systems adopt neutral operation mode with no-grounded or arc-extinguishing coil grounded.The faults caused by small-current grounding systems are most common with single-phase ground faults.In the event of a fault,over-voltage will be caused in the power system.Insulation of the system may even cause harm to the maintenance personnel.In order to quickly find the fault,it is necessary to analyze the cause of the fault and find fault lines to ensure stable operation of the power system.The power system with neutral arc-suppressed coil grounded,also known as resonant grounding system,is basically ineffective because of the compensation effect of the arc suppression coil.Therefore,this paper mainly studies the transient characteristics after single-phase earth fault and the line selection scheme based on transient signals.This article first introduced the development and summary of the line selection method.Under the rapid development of technology at home and abroad,it analyzed the existing methods and their significance so far,and analyzed the resonant grounding system to obtain the operating principle of the resonant grounding system.Through analyzing and summarizing the operating characteristics under faults,the characteristics of the faults are discussed in detail.The line selection method is proposed through the changes in the state variables,and the harmonics of the current and voltage at the time of ground fault are analyzed to study a method based on VMD decomposition and energy.Operator’s Resonance Grounding System Fault Line Selection Scheme.At the same time,the theoretical study of the principle,scope of use,and the inadequacies of the scheme are studied,and the wavelet modulus maximum method is added for comparative analys is.In the electromagnetic transient software ATP,a distribution network model is set up,a single-phase ground fault is set in the model,fault data is extracted and sent to a numerical simulation software MATLAB for fault information analysis.The simulation verifies that the VMD routing method is effective;The program analyzes the fault samples that change at a time and further validates the effectiveness of the solution.Finally,it discusses the reliability of line selection under different operating fault conditions,including different fault angles,different fault resistances,and in the case of the influences of the noise.