Research On Partial Discharge Detection Technology Of Electrical Equipment In Railway Substation

With the rapid development of modern high-speed railways in China,the ability of traction substations to provide safe and stable power supply is especially necessary for the operation of electrified railways.Most of the faults generated by the electrical equipment of railway substations during operation are mainly insulation faults caused by the aging of equipment insulation.In the routine maintenance of railway substations,regular detection of partial discharges can improve the safety performance of railway power systems,help operation and maintenance personnel understand the operation of high-voltage electrical equipment in substations,and can take timely measures to prevent small insulation Hidden dangers lead to major electrical accidents.This paper analyzes the relevant principles of the partial discharge detection method of high-voltage electrical equipment.In order to understand the propagation characteristics of partial discharge phenomenon more clearly and intuitively,this paper establishes the switch in the Solid Works software through the Finite difference time domain method(FDTD)Cabinet physical model,and import it as a.sat file to XFDTD for simulation analysis.The relationship between the electric field intensity of the partial discharge of the switch cabinet of the substation and the observation position,excitation source amplitude,pulse width and other factors is explored.In addition,by increasing the amplitude of the excitation source to simulate the characteristics of large volatility of the traction load caused by the passing of the electrified railway,this simulation result has certain reference value for the on-site detection test of the partial discharge of the traction load of the railway substation.This paper analyzes and diagnoses the maps of various partial discharge phenomena and interference phenomena,and summarizes the diagnostic criteria of partial discharge,so that the partial discharge detection standards can be better applied to on-site detection.The field test of Beijing-Shanghai High-speed Railway Substation was conducted by using UHF partial discharge detection method and ultrasonic detection method.Combined with the relevant characteristics of the traction load change of the train operation power supply system,the partial discharge of the switchgear and current transformer was tested and verified,and the cause of the partial discharge of the field equipment was analyzed.This study provides a field application basis for the partial discharge detection test of electrical equipment of railway substations,and has certain guiding value.