Abstract: A fault isolation apparatus includes a controller and a circuit breaker. When the circuit breaker is located on a bus connected to a DC/DC conversion unit, if a voltage collected by a first voltage collection terminal is a negative value, it indicates that input or output of the DC/DC conversion unit is reversely connected. In this case, if the circuit breaker is controlled to be opened, the DC/DC conversion unit can be prevented from being connected in series to other parallel DC/DC conversion units. If a voltage collected by a first voltage collection terminal is low and a current collected by a current collection terminal is large, it indicates that the DC/DC conversion unit is short-circuited. In this case, if the circuit breaker is controlled to be opened, another component connected in series to the DC/DC conversion unit can also be prevented from backfeeding energy to the DC/DC conversion unit.

Abstract: A power converter includes a power conversion circuit, a relay, and a controller. The power conversion circuit can be configured to implement conversion from a direct current to an alternating current. The relay can be configured to implement on-grid and off-grid switching. The controller can be configured to control switch-on/off of switches in the power conversion circuit and the relay. When a positive direct current bus has a short circuit to ground, the controller switches off a relay of a corresponding phase when any phase of grid voltage is negative. When a negative direct current bus has a short circuit to ground, the controller switches off a relay of a corresponding phase when any phase of grid voltage is positive.

Abstract: A direct current-direct current conversion circuit includes: an input inductor, a first capacitor, a second capacitor, a flying capacitor, a first switch, a second switch, a first inductor, a first diode, a first buffer circuit, a third switch, a fourth switch, a second inductor, a second diode, and a second buffer circuit. A power supply, the input inductor, the first diode, the second diode, the first capacitor, and the second capacitor are sequentially connected in series. A first terminal of the flying capacitor is connected between the first diode and the second diode. A second terminal of the flying capacitor is connected between the first switch and the third switch, and the second terminal of the flying capacitor is further connected between the second switch and the second inductor.

Abstract: A direct current-direct current conversion circuit includes: an input inductor, a first capacitor, a second capacitor, a flying capacitor, a first switch, a second switch, a first inductor, a first diode, a first buffer circuit, a third switch, a fourth switch, a second inductor, a second diode, and a second buffer circuit. A power supply, the input inductor, the first diode, the second diode, the first capacitor, and the second capacitor are sequentially connected in series. A first terminal of the flying capacitor is connected between the first diode and the second diode. A second terminal of the flying capacitor is connected between the first switch and the third switch, and the second terminal of the flying capacitor is further connected between the second switch and the second inductor.

Abstract: A fault isolation apparatus includes a controller and a circuit breaker. When the circuit breaker is located on a bus connected to a DC/DC conversion unit, if a voltage collected by a first voltage collection terminal is a negative value, it indicates that input or output of the DC/DC conversion unit is reversely connected. In this case, if the circuit breaker is controlled to be opened, the DC/DC conversion unit can be prevented from being connected in series to other parallel DC/DC conversion units. If a voltage collected by a first voltage collection terminal is low and a current collected by a current collection terminal is large, it indicates that the DC/DC conversion unit is short-circuited. In this case, if the circuit breaker is controlled to be opened, another component connected in series to the DC/DC conversion unit can also be prevented from backfeeding energy to the DC/DC conversion unit.