Research On Insulation Fault Location Method Of Electric Vehicle High Voltage System

With the depletion of oil resources,the traditional automobile industry has been greatly affected,and electric vehicles have developed rapidly.At present,the development and research of electric vehicles have been included in the national hightech research and development plan.Aiming at the problem of insulation grounding(body)of electric high-voltage systems of electric vehicles,this paper relies on the related topics of electric vehicles to conduct an in-depth study on the topology and grounding positioning principles of high-voltage systems of electric vehicles,and proposes an electric high-voltage electric vehicle System insulation grounding positioning method,and built an experimental platform to verify its rationality,related work is summarized as follows:First,through the analysis of the electric vehicle electrical high-voltage system topology and the existing insulation detection technology,a ground fault location strategy based on the access resistance method is proposed.That is,two sampling resistors with the same resistance value are connected to the positive and negative busbars of the power battery according to the access resistance method to measure the voltage across the sampling resistor;the analysis of the voltage waveforms at both ends of the sampling resistor determines the location of the ground fault in the high-voltage system.Secondly,in order to study the characteristics of the sampled voltage waveforms at different grounding locations,Simulink was used to build a high-voltage system model to simulate the grounding fault scenario at different locations to obtain their respective sampled voltage waveform data;the frequency components obtained by Fourier decomposition of the sampled voltages were analyzed.Research and analysis.According to the characteristics of the sampled voltage at different grounding locations,a set of ground fault location methods for high-voltage systems are summarized.Finally,an electric vehicle high-voltage system drive system experiment platform was built to verify whether the characteristics of the sampled voltage and the simulated structure in the actual simulated ground fault are the same.