| 摘要 |
PURPOSE:To prevent the vibration of hunting by inserting an internal voltage suppressor in which a switch and a resistor are connected in parallel with a field circuit, and controlling the opening and closing of the switch by the recovery of the system voltae to the prescribed value or higher and the reduction of the input power to the prescribed value or lower. CONSTITUTION:The armature winding 1a of a synchronous motor 1 is connected through a switch 2 to a power system, and the field winding 1b is connected through an internal voltage suppressor in which the winding 1b is connected in parallel with a resistor 5 and a switch 6 is connected to an exciter 4. A voltage detecting relay 9 and a power detecting relay 10 are provided at the output side of the winding 1a, and when the voltage of a power system instantaneously falls and recovers, the switch 6 is opened by the operation of the relay 9 to insert the resistor 5, the fact that the flowed power decreased to the prescribed value is detected by the relay 10 to reapply the switch 6. Accordingly, the flow of excess power at the system voltage recovery time can be suppressed to prevent the hunting from occurring. |
