Patent ID: 9306472
Filing Date: 2016-04-05
CPC Classification: H02M

Claim Text:
1. A power supply device comprising: a first switching leg in which a series circuit of a first switching element and a second switching element is connected between DC terminals; a second switching leg in which a series circuit of a third switching element and a fourth switching element is connected between the DC terminals; a first capacitor leg in which a series circuit of a first capacitor and a second capacitor is connected between the DC terminals; a second capacitor leg in which a series circuit of a third capacitor and a fourth capacitor is connected between AC terminals and in which a connection point of the third and fourth capacitors and a connection point of the first and second capacitors are connected by a neutral point connection line; a first inductor connected between a connection point of the first and second switching elements and one of the AC terminals; a second inductor connected between a connection point of the third and fourth switching elements and another of the AC terminals; a controller configured to control the first to fourth switching elements; an AC power supply connected between the AC terminals and the connection point of the third and fourth capacitors; and a DC power supply connected between the DC terminals, wherein the controller is configured to operate the switching elements of the first and second switching legs so as to charge the first and second capacitors to a voltage higher than a voltage crest value of the AC power supply by using power of the AC power supply, wherein the controller is configured to operate the switching elements by comparing voltages of the first and second capacitors and a set voltage, and configured to make the third and fourth switching elements in the second switching leg in an off-state and make the first and second switching elements in the first switching leg alternately in an on-state to charge the first and second capacitors to a voltage higher than the voltage crest value of the AC power supply, and wherein the set voltage is determined to a voltage higher than the voltage crest value of the AC power supply.