Ac power source apparatus

An AC power source apparatus comprising:

• a first AC power generator having a first switch and configured to generate a first AC voltage from a DC voltage of a first DC power source by way of an ON/OFF operation of the first switch and output the first AC voltage to a first end of a load;
• a second AC power generator having a second switch and configured to generate a second AC voltage from a DC voltage of one of the first DC power source and a second DC power source by way of an ON/OFF operation of the second switch and output the second AC voltage to a second end of the load, the second AC voltage having a phase difference of about 180 degrees with respect to the first AC voltage;
• a controller configured to control an ON duty of the first switch thereby controlling first AC power, set a phase difference for the ON/OFF operation of the second switch with respect to that of the first switch, and control an ON duty of the second switch thereby controlling second AC power;
• and
• a phase difference controller configured to control the phase difference set for the ON/OFF operation of the second switch so that output voltage or output current of the second AC power generator is equalized with that of the first AC power generator.