Research On Radiation Modeling And Simulation Of Traction Converter

With the improvement of traction converter internal equipment working frequency,the electromagnetic compatibility(EMC)problem has become the key factor that affect the normal work of the converter,to establish the simulation model of traction converter and realize the numerical simulation of various EMC problems of converter are necessary for studying and predicting the EMC problem,however,the actual converter model is complicated,it is bound to cause the simulation time is too long or even difficult to simulate,so optimizing the converter model is necessary.In this paper,the subway traction converter of a factory is taken as the research object.Based on the interference mechanism of the converter and its own electromagnetic characteristics,the actual converter model is optimized and simulated.Firstly,combined with the main circuit schematic diagram of traction converter,the common mode conduction path and the differential mode conduction path are modeled and analyzed.It is concluded that the du/ dt and di/ dt generated by IGBT high-speed switching on and off is the main conduction interference source.At the same time,from the perspective of radiation field,the relationship between IGBT and the parasitic parameters inside the box and the cable is modeled,and the mechanism of high frequency radiation generated by the traction converter is analyzed.On the basis of fully grasping the interference mechanism of the converter,aiming at the electromagnetic compatibility problems,such as numerous tiny structures and complex holes and gaps in the traction converter,the converter is optimized by using the perturbation theory and the gap transfer impedance technology,and the method combining the CST software simulation and theoretical calculation is adopted to verified the model processing method based on perturbation theory and the gap model processing method based on transfer impedance.Then,based on the box shielding theory and the hole leakage theory,the different shapes,numbers and angles of ventilation of the converter are simulated and analyzed,and the optimization opinions of the holes and the seams of the box are given.Finally,by building an electrical model with parasitic parameters,the IGBT current signals of the converter are obtained.Based on the simulation optimization method,the complex model and the simplified model are compared and analyzed respectively to obtain the correctness and reliability of the simplified model.The research content of this paper not only provides theoretical and simulation support for the structural design and rectification of traction converter EMC,but also provides the corresponding theoretical basis for the model simplification and simulation of traction converter.It can be used as a reference for the simplification and simulation of electric large size model.