| 摘要 |
PURPOSE:To safely start a synchronous motor by starting the motor as an induction motor and largely controlling the resistance of a field winding circuit when passing the twisting dangerous speed of a shaft in a speed range at the accelerating time. CONSTITUTION:When a synchronous motor 1 which is coupled directly with an industrial machine 2 is started, switches 10, 9 are opened, a switch 8 is closed to form a closed circuit through a discharging resistor 7 in a field winding circuit, and the motor is started as an induction motor through a starter 5. When approaching to the twisting dangerous speed of a shat system, the switch 8 is opened, and the resistance of a field winding circuit is increased infinitely, thereby reducing a pulsating torque, and passing through a dangerous speed range. Then, full voltage is applied by the starter 5, a field switch 10 is closed, and synchronized. Accordingly, the safe start can be performed readily without increasing the twisting vibration. |
