Patent ID: 8044622
Filing Date: 2011-10-25
Classification: H02P

Abstract:
1. A sensorless control apparatus of a synchronous motor, which estimates a rotational phase angle of a rotor having electrical saliency and controls the synchronous motor by a PWM inverter, comprising: a PWM modulation unit which modulates a control instruction, which is input, on the basis of PWM, and outputs a gate signal to each phase switching element of the inverter; a high-frequency component arithmetic unit which calculates, at each time of switching of the inverter, a high-frequency component of a current which flows in the synchronous motor by a voltage which is determined by the PWM modulation unit and is output from the inverter; an index arithmetic unit which calculates an index proportional to an estimation error of the rotational phase angle, from the high-frequency component of the current on rotational coordinate axes which rotate in sync with rotation of the rotor; and a rotational phase angle estimation unit which executes an estimation arithmetic operation of the rotational phase angle by using the index.