| 摘要 |
PURPOSE:To enable the simple suppression of the secondary overvoltage of a wound-rotor type induction machine by firing a thyristor in a thyristor circuit to shortcircuit between the respective phases of the secondary coils when overvoltage is inducted in the secondary coils. CONSTITUTION:Thyristor circuits 4, 5, 8, 9, 12, 13 connected in Graets connection are connected in anti-parallel with the respective phases of the secondary coils of a wound-rotor type induction machine 1 connected at the primary coil to an AC power source, one ends of the DC terminals of the thyristor circuits of the respective phases are commonly connected, and the AC terminals of the respective thyristor circuits are respectively connected to an AC power source via insulating transformers 16. When an overvoltage is produced in the secondary coils of such secondary exciting controller, the thyristors of the thyristor circuits are fired to shortcircuit between the phases of the secondary coils. For example, the overvoltage is detected by the overvoltage detectors 21-24, and the above fire controls are respectively performed via gate amplifiers 17-20. |
