Power supply apparatus including AC-DC converters connected in parallel and driven based on load current

A power supply apparatus comprising:

• a plurality of converters connected in parallel to a three-phase alternating-current power supply to convert alternating-current power from the three-phase alternating-current power supply into direct-current power to supply the direct-current power to different loads;
• a phase current detector to detect current flowing through a first phase line, a second phase line, and a third phase line of the three-phase alternating-current power supply;
• and
• a load current detector to detect load current of the plurality of converters;
• wherein
• each of the plurality of converters includes a first AC-DC converter an input of which is electrically connected to the first phase line and the second phase line, a second AC-DC converter an input of which is electrically connected to the first phase line and the third phase line, and a third AC-DC converter an input of which is electrically connected to the second phase line and the third phase line;
• the first AC-DC converter, the second AC-DC converter, and the third AC-DC converter are connected in parallel to each other by a common output;
• each of the first, second, and third AC-DC converters that is driven maintains balance of an output current, the power supply apparatus further comprising:
• a determiner that determines whether switching between a driven state and a stopped state of the first AC-DC converter, the second AC-DC converter, and the third AC-DC converter is performed based on a detection result from the load current detector, while maintaining the output current of each of the first, second, and third AC-DC converters to be substantially the same;
• a selector that, if the determiner determines that the switching is performed, selects targets to be driven and to be stopped from the first AC-DC converter, the second AC-DC converter, and the third AC-DC converter based on a detection result by the phase current detector;
• and
• a controller that switches between the driven state and the stopped state of the first AC-DC converter, the second AC-DC converter, and the third AC-DC converter based on a selection result by the selector;
• each of the first, second, and third AC-DC converters is configured to perform a current sharing function;
• and
• the determiner maintains the output current of each of the first, second, and third AC-DC converters to be substantially the same based on the current sharing function.