Bidirectional converter and control method thereof

A power supply apparatus comprising:

• a low-voltage direct current-direct current converter (LDC) configured to convert a voltage of a high-voltage battery to supply power;
• a first low-voltage battery configured to be charged by receiving the power from the LDC and supply power to a predetermined load;
• a bidirectional converter configured to convert a voltage supplied from the LDC and control a charge amount of a second low-voltage battery;
• the second low-voltage battery configured to be charged by receiving power from the bidirectional converter and supply power to a dual power source load;
• a first relay disposed between the LDC and the first low-voltage battery;
• a second relay disposed between the bidirectional converter and the second low-voltage battery;
• a battery sensor configured to measure a voltage of the second low-voltage battery;
• and
• a control unit configured to control the bidirectional converter to charge the second low-voltage battery.