Power conversion apparatus and power conversion system

A power conversion system comprising:

• a first battery including a first terminal and a second terminal;
• a 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 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 capacitor to each other;
• a power conversion apparatus;
• and
• a second battery, wherein
• the power conversion apparatus includes
• a first power terminal including a first coupling terminal and a second coupling terminal, the first coupling terminal being coupled the first terminal of the capacitor, the second coupling terminal being coupled to the second terminal of the capacitor,
• a switching circuit coupled to the first power terminal and including a plurality of first switching devices, the first switching devices being configured to be turned on and off based on a first driving signal,
• a transformer including a first winding and a second winding, the first winding being coupled to the switching circuit,
• a rectifying circuit coupled to the second winding and including a plurality of second switching devices, the second switching devices being configured to be turned on and off based on a second driving signal,
• a smoothing circuit coupled to the rectifying circuit,
• a second power terminal coupled to the smoothing circuit, and
• a control circuit configured to control operations of the first switching devices and the second switching devices, and
• the control circuit is configured to, in a first period before electric power is supplied from the first power terminal toward the second power terminal,
• generate a first threshold that increases with passage of time, and
• perform, when a voltage value of a voltage at the first power terminal reaches the first threshold, switching from an output state to an output stop state, or switching from the output stop state to the output state, the output state being a state in which the second driving signal is outputted, the output stop state being a state in which output of the second driving signal is stopped.