Position sensorless controller for a permanent magnet synchronous motor

The fundamental current detector 8 detects the current at zero voltage vector period V7 or V0 of the PWM control. Current change detection unit 11 calculates the current difference of the actual current which corresponds to the current differential from the current detection value. Current difference component calculation unit 12, an electromotive force is calculated from the voltage drop and the inductance L and the angular frequency command omega Correcting angular frequency command calculating unit 13 to 15, by adding the current difference and the current difference component of the actual current, multiplied by the filter and the correction gain, the angular frequency weighting function K