Synchronous PWM Control With Carrier Wave Phase Shifts for Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors (PMSMs) are utilized in a wide range of applications as high-power-density and highly efficient drive sources. However, a PMSM generates electromagnetic vibration and loss caused by space and time harmonics. In this article, we propose a synchronous pulsewidth modulation control method for shifting the carrier wave phase against the modulation wave phase. As the proposed control matches the vibration frequencies caused by space and time harmonics, the pulsation caused by the space harmonics is canceled out by the pulsation caused by the time harmonics with the phase shift of the carrier wave. Experiments on the proposed control demonstrate that vibration at a specific frequency was reduced by 46% at 7900 rev/min. In addition, to change the carrier phase with small
d
-axis current harmonics, magnet eddy-current loss was reduced by shifting the carrier wave phase. The temperature of a magnet was measured in a heat-run test, and the temperature rise of the magnet could be suppressed by 5 K.