Outputs from first and second DC power supplies are controlled based on a first reactor current and a second reactor current. For controlling an output from a corresponding DC power supply, a relative maximum point and a relative minimum point as two inflection points are provided in a high current of the first and second reactor currents in one control cycle, by controlling on and off of switching elements. In a low current of the first and second reactor currents, inflection points more than in the high current are provided. Each of the inflection points on a side of the high current is provided at timing identical to the inflection point on a side of the low current.