| 摘要 |
PROBLEM TO BE SOLVED: To obtain a safe and secure starting method which can protect elements from breakdown, etc., by a method, wherein energy is accumulated in the capacitor of an energy recovery circuit before the normal operation of a power converter is started and the energy is regenerated to a DC power supply unit. SOLUTION: If a GTO (self-extinguishing semiconductor switching device) 1a is turned off, a snubber capacitor 4a is discharged, and energy which has been accumulated in a snubber capacitor 4a is transferred to a recovering reactor 8a and, at the same time, recovered by a recovering capacitor 7a. When the discharge of the snubber capacitor 4a is finished, a snubber diode 5a is turned to be electrically continuous, and the energy transferred to the reactor 8a is recovered by the recovering capacitor 7a. The energy recovered by the recovering capacitor 7a is, partially being supplied as the energy of the power supply of a gate drive circuit 12a, regenerated to a DC power supply side 100 by an energy regenerating circuit 11a, so that the initial charging of the capacitor can be performed before the normal operation is started. |
