POWER SUPPLY DEVICE FOR RECIRCULATION PUMP AND CONTROL METHOD THEREOF

PROBLEM TO BE SOLVED: To perform repair of a failure point or maintenance inspection of a semiconductor power conversion circuit without stopping a recirculation pump in the event of a single failure of a power supply device for the recirculation pump or in maintenance inspection of the power supply device. SOLUTION: This variable-voltage, variable-frequency power supply device for driving the recirculation pump includes semiconductor power conversion circuits 16 and 17 and a speed control device 12 controlling the semiconductor power conversion circuits. When part of the conversion circuits 17 and 18 is laid in a non-operating state, the part of the non-operating state is electrically separated, and the output of the power supply is temporarily stopped to idle the recirculation pump. Thereafter, the power supply device is restarted before the recirculation pump is perfectly stopped, whereby the operation is continued without stopping the recirculation pump. COPYRIGHT: (C)2006,JPO&NCIPI