Motorsteuerungsvorrichtung

摘要

In an arrangement having an electric power inverter (3) which applies a voltage to an AC motor (1) and a control unit (4) which calculates a voltage command value applied in PWM signals, detection use voltages Vup, Vvp and Vwp are applied in synchronism with PWM signal generation use carrier waves in the control unit (4) as well as motor currents iv and iv are detected in response to current detection pulses Pd in synchronism therewith. In a magnetic pole position detection unit (12), counter electromotive forces of the synchronous motor (1) are estimated from a relationship between the detection use voltages Vup, Vvp and Vwp and current difference vectors of the motor current to determine a magnetic pole position &thetas; through calculation. The determined magnetic pole position &thetas; is inputted to coordinate conversion units (8, 11) and a motor speed detection unit (13). Thereby, a motor control device having a control characteristic of a good response property with no magnetic pole position sensor is provided for a control system of a synchronous motor.