Analysis of losses of permanent magnet synchronous motor with PWM supply

This paper investigates the additional losses introduced by PWM supply in surface mounted permanent magnet synchronous motor (PMSM). An analytical model is developed to discuss additional iron loss, and an analytical model of PM eddy current loss which according for eddy current reaction is also presented. Finite element method (FEM) are used to calculate the characteristic of additional losses distribution and the experiment results verify the conclusion. Both the FEM and experiment verified the relationship between the additional losses and PWM supply factors, such as modulation index, frequency-carrier ratio. The relationship between additional losses and current total harmonic distortion (THD) are studied by analytical analysis too.