POWER CONVERSION DEVICE AND FUEL CELL SYSTEM PROVIDED THEREWITH

A power converter of the present invention is configured to convert DC power generated by a power generator (1) into AC power. The power converter includes: a boost converter circuit (3) configured to boost an output voltage of the power generator (1); an inverter circuit (5) configured to convert an output voltage of the boost converter circuit (3) into AC power and to interconnect the AC power with a power system (2); a buck converter circuit (8) configured to perform power conversion of output power of the boost converter circuit (3) and to supply resultant power to an internal load (60); and a controller (9). The controller (9) is configured to control the output voltage of the boost converter circuit (3) to be lower than or equal to a second voltage value which is less than the maximum value of AC voltage of the power system (2), in a case of supplying output power of the power generator (1) to the internal load (60) via the boost converter circuit (3) and the buck converter circuit (8).