POWER CONVERSION SYSTEM

A DC/DC converter includes a power conversion unit for converting input voltage to required voltage, a first control unit for driving the power conversion unit, a power supply device which supplies power to the first control unit and uses an output of the DC/DC converter or a battery as a power supply source, and a power supply function for controlling supply of power to the power supply device. The power supply function is controlled with respect to supply of power, by a second control unit of a power conversion device during a standby state of the DC/DC converter.