Abstract：The common-mode equivalent circuit model of the motor is the basis for analyzing the electric

erosion of bearings，especially for analyzing the technical problems and experimental phenomena of shaft voltage

and shaft current，among which the centralized equivalent model is an important calculation basis for the key index

of bearing electric erosion that is bearing voltage ratio（BVR），which can be evaluated in the early stage of motor

design. The accurate simulation calculation of the distributed capacitance parameters of the centralized equivalent

model were studied in depth. Firstly，the simulation calculation and comparison of the two-dimensional single-slot

and full-model motors were carried out. Secondly，the influence of the stator winding end and the rotor end ring on

the stray capacitance was considered，and the three-dimensional motor model was simulated and calculated，and the more accurate distributed capacitance parameters were obtained through comparative study. Finally，the parameters of YQ190-14 type traction motor were taken as an example，and the simulation calculation results and test results were compared and analyzed，and the accuracy of the simulation calculation results was verified.

      Key words：electric erosion of bearings；centralized equivalent model；distributed capacitance parameters；

accurate simulation calculation；actual determination