Fine servo system based on new over-modulation with priority given to d-axis voltage for IPMSM

This paper proposes a new fine servo system based on a new over-modulation method with priority given to d-axis voltage for interior permanent magnet synchronous motor (IPMSM). The proposed over-modulation method gives priority to the d-axis voltage to avoid the d-axis voltage saturation, and increases the amplitude of inverter output voltage to achieve the quick torque and speed responses under voltage saturation. The proposed system prevents oscillatory current responses caused by the windup phenomenon in current controllers, and achieves quick and stable speed response through the stable current response and the large amplitude of inverter output voltage. The experimental results confirm the effectiveness of the proposed servo system.