| 摘要 |
PURPOSE:To enable continuous power supply to a minimum necessary load even upon failure of a CVCF inverter by continuously feeding the output power from a VVVF inverter to a first load through switching operation of a switching means when power supply to the first load is disabled. CONSTITUTION:Upon failure of a CVCF inverter 3, switches 5, 8 are opened while a switch 10 and an auxiliary switch 11 are closed. Consequently, the CVCF inverter 3 and a load 9 are disconnected, and a VVVF inverter 4 is connected to the side of an AC filter 6. Since the VVVF inverter 4 is forcibly transferred to commercial frequency operation, AC commercial frequency power containing high frequency component, produced through the VVVF inverter 4, is fed to the AC filter 6 where the high frequency component is removed and AC commercial frequency power is fed to a load 7. |
