| 摘要 |
PURPOSE:To turn OFF in a safely operating range by inserting a current conversion rate limiter to the input side of a power converter, and discharging stored energy of a surge voltage absorber when the converter is turned OFF. CONSTITUTION:A current change rate limiter in which a reactor 13 and a diode 14 are connected in parallel is inserted to between a power converter 2 in which self-extinguishing elements are connected in a bridge and a DC power source 1. Further, an electric valve 16 is connected through a current limiting impedance 17 with both ends of a capacitor 5 which forms a surge voltage absorber. When an overcurrent is detected by an overcurrent detector 8, the valve 16 is closed to discharge the stored energy of the capacitor 5, and the elements in the converter 2 are turned OFF after a time slightly delayed by a relay 18. |
