A primary circuit and a secondary circuit each have a switching element, each operate as a power conversion circuit while the switching element is activated, and each operate as a rectifier circuit while the switching element is deactivated. While a generator provided at the primary side of a first power conversion device is stopped, a controller activates the switching element of the secondary circuit and deactivates the switching element of the primary circuit. Accordingly, the first power conversion device converts electric power input from the secondary side and supplies electric power for causing the generator to operate. While the generator is operated, the controller activates the switching element of the primary circuit and deactivates the switching element of the secondary circuit such that the first power conversion device converts electric power supplied from the generator and outputs the converted electric power to the secondary side.