| 摘要 |
PROBLEM TO BE SOLVED: To enable continuation of the power feeding to minimum loads required, even though a constant-voltage constant-frequency inverter has been failed by operating a variable-voltage variable-frequency converter with constant- voltage constant-frequency operation by means of transfer operation of transfer means, when power feeding to a first load has become impossible. SOLUTION: If power feeding to a load 7 becomes impossible by the operation stop of a constant-voltage constant-frequency(CVCF) inverter, switches 5, 8 are switched to a closed state, and a switch 10 and an auxiliary switch 11 is switched to a closed state. By closing the switch 5, a CVCF inverter 3 is disconnected, and a load 9 is also separated by opening the switch 8. Also, by the closing operation of the switch 10, a variable-voltage variable-frequency(VVVF) inverter 4 is connected to an AC filter 6 side. In this state, the auxiliary switch 11 is also closed, and shifting to the constant-voltage constant-frequency operation occurs, and the power feeding to the load 7 is continued. |
