| 摘要 |
PURPOSE:To obtain a high voltage thyristor switch having high durability with simple constitution by omitting the wiring construction of a line connecting neutral points. CONSTITUTION:When a high voltage thyristor switch 7 is turned on, the ignition pulses are applied to thyristor elements 8-11 of the 1st and 2nd phases at the zero point of the voltage detected by a transformer 17. Then the ignition pulses are applied to thyristor elements 12 and 13 of the 3rd phase at the zero point of the voltage which is detected by a voltage detector 18 at an extremely high response speed. This minimizes the overcurrent in an ON mode. When the switch 7 is turned off, the ignition pulses of the elements 8 and 9 are erased at the zero point of the current detected by a transformer 14. Then the ignition pulses of thyristor elements 10-13 are erased at the zero point of the current detected by a transformer 15. Thus the overvoltage can be minimized in an OFF mode. |
