Power supply circuit, power supply device, and power supply system

A power supply device, comprising a power supply circuit, wherein the power supply circuit comprises:

• a bus, a first port, a second port and power ports;
• a first branch having a first end electrically connected to the bus, and a second end electrically connected to the first port;
• a second branch having a first end electrically connected to the bus, and a second end electrically connected to the second port;
• a plurality of third branches, each of the plurality of third branches having a first end electrically connected to the bus, and a second end electrically connected to a corresponding one of the power ports, and each of the plurality of third branches being provided with a first switch;
• and
• a control circuit connected to a drive terminal of the first switch of each of the plurality of third branches, the control circuit being configured to control the first switch of each of the plurality of third branches to be turned on or off,
• wherein each of the first port and the second port is configured to be connected to a load or an inverter, and each of the power ports is configured to be connected to a power grid or a power source.