Research on equivalent capacitance model of couplings of EMU

Establishing an equivalent circuit model for leakage current circuits is an important approach to studying coupling leakage current, and the equivalent capacitance of coupling is a key parameter in the circuit model. This thesis analyzes the equivalent capacitance structure of coupling based on meshing state of the tooth pairs during operation. By analyzing the elastic deformation of coupling under stress, formulas for calculating the oil film area and thickness between the inner and outer teeth were derived, and the equivalent capacitance model of coupling was established. Taking a certain type of EMU coupling as the research object, the equivalent capacitance was calculated through the equivalent capacitance model of coupling and finite element simulation. The error rate between results of the model calculation and the results of finite element simulation calculation was 5.83%, which verified accuracy of model. The research results can provide reference for the study of the equivalent circuit model of the leakage current circuit of EMU.