According to the present invention, in position sensorless control for switching between a 120-degree energization scheme for a low-speed region and a 180-degree energization scheme for a mid-to-high-speed region, stable and highly accurate speed control characteristics are provided by suppressing speed deviation Δωr in the low-speed region, and by preventing current jump-up caused by a discontinuous rotational speed occurring during switching to the mid-to-high-speed region. In the case of driving in the 120-degree energization scheme, a voltage command value is corrected such that an estimated speed value or a detected speed value follows a speed command.