| 摘要 |
PURPOSE:To shorten the time until a synchronization is obtained by detecting the rotating speed and a load current of a synchronous motor and controlling it in response to a load torque. CONSTITUTION:When a synchronous motor 1 is started, breakers 2, 8 are closed. An inverter 4 is controlled in accordance with the output signal of a distributor 11. When the speed of the motor 1 is lower than 5-10% of the synchronous speed, a relay 13-1 will operate to intermittently control a converter 6, and the commutation of an inverter 4 is performed. When the speed of the motor 1 is higher than 5-10% of the synchronous speed, a relay 13-2 will operate, and the converter 6 is controlled by the set current value set by a setting unit 15-1 to accelerate the motor 1 to the vicinity of the synchronous speed. When the speed of the motor 1 becomes higher than 99% of the synchronous speed, a relay 13-3 will operate, and the converter 6 is controlled in response to the set current value to obtain a torque corresponding to the load torque in the synchronous speed set by a setting unit 15-2. |
