Iron Loss Analysis of an Electrically Excited Synchronous Motor Under Space Vector PWM for Automotive Traction Application

This study quantifies the impact of non-sinusoidal currents on iron loss in an electrically excited synchronous motor (EESM) using finite element analysis (FEA). The motor drive system considered is for automotive traction applications. Field-oriented control (FOC) with space vector pulse width modulation (SVPWM) is implemented for stator current control of the EESM in the JMAG environment. A constant rotor current source is used. The control circuit and FEA are simulated together and the iron loss is calculated for different operating points to cover relevant operating points of the motor. Switching frequencies of 5, 10, and 20 kHz were considered. The influence of SVPWM control on iron loss is compared to the iron loss with the motor supplied by a sinusoidal current supply. The results show that the iron loss is always increased with SVPWM and that lower switching frequencies have higher iron losses due to higher harmonic distortion in the phase currents