Reduction of iron loss in stator core using an optimum pulse pattern for high-speed IPMSM

This study proposes a reduction method for iron loss in stator core using the optimum pulse pattern for a high-speed interior-permanent-magnet-synchronous-motor (IPMSM). In this paper, a simple evaluation function for iron loss of stator core in a pulse-width-modulation (PWM) drive is introduced. In particular, the iron loss in stator core is approximately estimated from the flux level obtained from the integral of the line-to-line voltage of the PWM drive. In addition, the pulse pattern is optimized to reduce the iron loss in stator core based on the introduced evaluation function. To validate the evaluation function, the correlation coefficient between the evaluation value and the measured iron loss is calculated in 12 random pulse patterns applied to the inductor and IPMSM. As a result, the correlation coefficients are 0.991 and 0.982 in the inductor and IPMSM, respectively. In addition, the iron loss of the IPMSM with the optimum pulse pattern is reduced by 8.5% and 3.7% in comparison with a carry-asynchronous PWM and carry-synchronous PWM, respectively. © 2021 The Institute of Electrical Engineers of Japan.