When a control device simultaneously drives first and second direct-current power converter circuits, the control device can arbitrarily control a first voltage and a second voltage, and a load voltage by changing at least one of first and second duties. The control device generates a loop current, which discharges a first power source and charges a second power source, or a loop current, which charges the first power source and discharges the second power source, in a loop circuit where a first reactor and a second reactor are connected in series.