Power conversion device

A power conversion device comprising:

• a first smoothing circuit connected to a first electric device;
• a second smoothing circuit connected to a second electric device;
• a first bridge circuit connected to the first smoothing circuit;
• a transformer having a primary side connected to a third electric device and a secondary side connected to the first bridge circuit and the second smoothing circuit;
• and
• a controller for performing switching control of the first bridge circuit, wherein
• the controller varies a duty ratio of the first bridge circuit at a frequency higher than a cutoff frequency of the first smoothing circuit and a cutoff frequency of the second smoothing circuit, and the controller controls a constant component of the duty ratio to control power exchange between the first electric device and the second electric device, and at the same time, controls a phase of a varying component of the duty ratio to control power exchange to and from the third electric device.