A converter ECU obtains a temperature increase start signal indicating start of temperature increase of a power storage unit from each sensor and ECU provided in a vehicle. In addition, the converter ECU obtains allowable electric power of the power storage unit from a battery ECU and obtains a power storage unit temperature from a temperature detection unit. When any of the obtained power storage unit temperatures is lower than a corresponding temperature lower limit value, the converter ECU generates a temperature increase instruction for the power storage unit of which temperature is lower than the corresponding temperature lower limit value, based on the temperature increase start signal. In addition, the converter ECU selects one control mode from among a plurality of control modes set in advance, based on the generated temperature increase instruction, and sets that mode as the control mode for a converter.