Modeling And Simulation Of Electromagnetic Interference Of High-Voltage Electronic System Based On Field-TL-Circuit Coupling

In the limited space of high-voltage electronic system,the transient high current generated by capacitor discharge can cause electromagnetic interference seriously with low-voltage sensitive circuits through radiation and conduction coupling.Therefore,compared with general equipment,high-voltage electronic system has more obvious electromagnetic compatibility problems.In order to predict and solve the electromagnetic compatibility problems of some high-voltage electronic system in the stage of test and demonstration,research on modeling and simulation of electromagnetic interference based on field-TL-circuit coupling is carried out.The main contents are as follows:(1)Research on field-TL-circuit co-simulation of electromagnetic interference.Based on the CST simulation platform,the field-TL-circuit co-simulation model of electromagnetic interference of the high-voltage electronic system is established through the analysis of co-simulation method and electromagnetic interference mechanism,including the modeling and analysis of excitation signals,the establishment of passive structure model and active circuit model of the system.The numerical simulation methods required by the simulation task are determined,then the field-TL-circuit co-simulation is carried out,and simulation results of radiated and conducted interference of system are obtained finally.(2)Research on analysis and simulation of key circuits under interference influence.A joint simulation method of grading circuits based on CST DESIGN STUDIO block is proposed.The accuracy of this method is verified by a simple example.Meanwhile,this method is applied to the system on the basis of analysis of crosstalk propagation path,and its power supply conversion circuit is selected as a sub-circuit to establish the joint simulation model.Then,the output fluctuation of key circuits under the influence of cable crosstalk is solved.According to the comparison with results and duration of independent simulation,the high-effectiveness of joint simulation is verified.(3)Research on cable crosstalk characteristics and suppression methods.Based on the multi-conductor transmission line equation in frequency domain,the theoretical calculation model for crosstalk of curved cables is derived through similarity transformation and chain-parameter matrix cascade.This model is used to analyze the relationship between crosstalk and the height above ground,the included angle,the separation distance,the degree of bending of cables.And the validity of the proposed model and the obtained laws are verified by experiments.After analyzing the characteristics of crosstalk and system object,the suppression measures of EMI are studied from the perspectives of changing the cables wiring and filtering the receiving end.The effectiveness of the measures is verified by comparison of simulation results.