A method for controlling a permanent magnet synchronous motor includes detecting an absolute angular position and using the angular position to calculate a rotational speed of the motor; detecting a voltage of a battery as a power source; calculating a compensated speed from a rotational speed of the permanent magnet synchronous motor based on a torque command, the rotational speed of the permanent magnet synchronous motor, and the battery voltage; generating a d-axis current command and a q-axis current command corresponding to the torque command and the compensated speed; calculating a d-axis voltage command and a q-axis voltage command based on the d-axis current command and the q-axis current command; converting the d-axis voltage command and the q-axis voltage command into three-phase voltage commands based on the detected absolute angular position; and controlling the operation of the permanent magnet synchronous motor based on the three-phase voltage commands.