Electric power conversion apparatus and electric power conversion system

An electric power conversion system comprising:

• a first battery including a first terminal and a second terminal;
• a second capacitor including a first terminal and a second terminal;
• a first switch provided on a path coupling the first terminal of the first battery and the first terminal of the second capacitor to each other;
• a second switch provided on a path coupling the second terminal of the first battery and the second terminal of the second capacitor to each other;
• an electric power conversion apparatus;
• and
• a second battery, wherein
• the electric power conversion apparatus includes
• a first electric power terminal including a first coupling terminal and a second coupling terminal, the first coupling terminal being coupled to the first terminal of the second capacitor, the second coupling terminal being coupled to the second terminal of the second capacitor,
• a switcher coupled to the first electric power terminal and including one or more switching devices,
• a transformer including a first winding and a second winding, the first winding being coupled to the switcher,
• a rectifier coupled to the second winding and including a switching circuit that includes a first switching device and a second switching device, the first switching device being operable based on a first control signal, the second switching device being operable based on a second control signal;
• a smoother coupled to the rectifier and including an inductor;
• a second electric power terminal coupled to the smoother and to the second battery;
• a controller configured to control operations of the switcher and the rectifier;
• and
• a driver configured to drive the switching circuit, based on an instruction from the controller, wherein
• the first switching device and the second switching device each include a first terminal, a second terminal, and a control terminal,
• the switching circuit further includes a first device provided on a first path and configured to clamp a voltage, the first path coupling the first terminal of the first switching device and the control terminal of the first switching device to each other,
• the driver includes a first output terminal and a second output terminal, and is configured to, based on a signal supplied from the controller, output the first control signal from the first output terminal and output the second control signal from the second output terminal, and
• the controller is configured to, in a predetermined period that is different from a period in which electric power is supplied from the first electric power terminal toward the second electric power terminal, control the operations of the switcher and the rectifier to cause electric power to be supplied from the second electric power terminal toward the first electric power terminal, and set an output impedance of the first output terminal of the driver to a high impedance state.