Inverter apparatus connected to a plurality of direct current power sources and dispersed-power-source system having inverter apparatus linked to commercial power system to operate

An inverter apparatus (4) includes a plurality of converters (5A-5D) each receiving a direct current power from respective plurality of solar cell arrays (2A-2D) having different output voltage ranges, and an inverter (6) transforming the direct current power from the plurality of converters (5A-5D) into an alternating current power and allowing the alternating current power to reversely flow into a commercial power system (10). The plurality of converters (5A-5D) have different voltage input ranges corresponding to the output voltage ranges of the plurality of solar cell arrays (2A-2D), and each control, based on a pulse frequency modulation control signal received from a corresponding converter control unit, an output voltage of corresponding one of the plurality of solar cell arrays (2A-2D), so that an output power from corresponding one of the plurality of solar cell arrays (2A-2D) becomes maximum.