| 摘要 |
PURPOSE:To accurately initialize and to drive a synchronous AC motor by obtaining a power factor when a torque becomes zero, and initializing with a position phase-shifted at 90 deg. of an electric angle from the position of the power factor as a commutation angle command of the power factor 1. CONSTITUTION:A pulse generator 31 for outputting an incremental pulse IP is connected to an output shaft of a synchronous AC servo motor 30, and the pulse IP is reversibly counted by a counter 22. The torque of the output shaft of the motor 30 is detected while varying a phase angle between the revolving magnetic field of a stator and a permanent magnet pole, a power factor when its torque becomes zero is obtained, and initialized at the position phase-shifted at 90 deg. of an electric angle from the power factor position as a commutation angle command of the power factor 1. Thus, the motor 30 can be driven by accurately initializing it without deviating a mechanical zero point. |
