基于高速列车接地系统参数对车体电流及过电压平衡的优化OA北大核心

Due to the increasing speed of high-speed trains,the grounding system faces new challenges.When the relative motion between the train and the track occurs,the phenomenon of ground backflow will be intensified,resulting in the rise of train body potential,the abnormity or even damage of bearing and ground carbon brush,insulation joint,on-board sensors and other problems.In view of the existing problems of grounding reflux and train body potential of high-speed trains and the failure of two-dimensional model of high-speed train grounding system to simulate and analyze the potential of the left and right sides of the same axle based on radial parameters,it is necessary to conduct a more perfect three-dimensional modeling of the integrated grounding system of high-speed trains.In order to suppress the grounding current and reduce the potential of the vehicle body,optimized analysis of the grounding mode and grounding parameters of the grounding system is conducted.In this paper,based on the measured data and theoretical analysis of the impedance and inductance parameters of the train body as well as the actual size parameters of the train body by the RCL tester,the three-dimensional circuit model of the integrated grounding system of the high-speed train is completed respectively from the aspects of traction transformer,overhead contact line,on-board transformer of high-speed train,high-voltage cable and train body under the premise of fully considering all the influencing factors.At the same time,combined with the dynamic grounding reflux test of the train passing under the on-line condition and the static overvoltage test of the high-speed train raising the pantograph and closing the VCB,the simulation results are compared with the measured results to verify the reliability of the three-dimensional model.Finally,based on the three-dimensional simulation model,the radial parameters of the docking system and the three-dimensional distribution of the protection grounding and working grounding are optimized.After optimization,the ground current flowing through the protection grounding of the train is reduced to different degrees,and the distribution becomes more uniform.Meanwhile,the potential of the train body is maintained within the safety limit.