| 摘要 |
PURPOSE:To easily restart after an accident is recovered by continuously operating a power converter to regenerate an accident current to be input to a DC link capacitor to a main circuit when a main circuit voltage at the time of a system accident reaches a predetermined voltage, and controlling a voltage of the capacitor to a constant voltage. CONSTITUTION:When a three-phase short-circuit accident occurs at a transmission line 8, etc., and a bus voltage detected by voltage detecting means 16 does not reach a predetermined voltage, a power converter 12 and an inverter 15 are stopped. Then, when a DC link capacitor voltage VC is raised due to an accident current to be input to the capacitor 13 through the inverter 15, energy stored in the capacitor is consumed by the operation of a chopper 14. On the other hand, when it is judged that the bus voltage reaches a predetermined voltage at the time of an accident, the inverter 15 is stopped, but the converter 12 is continuously operated to regenerate it. Thus, it is so controlled that the voltage VC becomes constant. |
