| 摘要 |
PROBLEM TO BE SOLVED: To enable accurate operation control of a synchronous motor, regardless of the application pattern of the motor. SOLUTION: When a synchronous motor is started, it is considered that the motor rotates at a revolution higher than a predetermined revolution so that the detection of an electrical angle is tried (step S120). If the electrical angle cannot be detected, the electrical angle is detected (step S160) by a 2nd method, which enables the detection of the electrical angle at a revolution lower than the predetermined revolution. Or the revolution of a rotor is detected by a 3rd method, and if the revolution is higher than the predetermined revolution, the electrical angle may be detected by the 1st method. Furthermore, if the revolution is lower than the predetermined revolution, the electrical angle may be detected by the 2nd method. As a result, when the synchronous motor is started, even if the rotor rotates already at a revolution higher than the predetermined revolution, the electrical angle can be detected accurately. |
