A stable field-weakening control using voltage phase operations in the high-power region

A field-weakening control is required in order to achieve high power output and stable control in the voltage saturation region. In this paper, a voltage phase-operated field-weakening control and a frequency-compensation control are presented. The voltage phase operation control adjusts the voltage phase command with the voltage maintained at the maximum value. Therefore the proposed control can provide higher output power. The frequency compensation control decreases motor speed command in the motor torque limit region, and the motor speed overshoot is thus suppressed. Experimental results show that the proposed controls are effective in suppressing motor speed overshoot and allowing high power output.