Charging and discharging control system

A charging and discharging control system, comprising:

• a charging control box, which comprises a control module, a communication module, a charging port, a discharging port, and a first controllable switch circuit, wherein the first controllable switch circuit is configured to achieve switching between the charging port and the discharging port, the charging port is used to be connected to a power grid, the discharging port is used to be connected to an external electrical device, and the communication module is configured to achieve communication connection between the control module and an electric automobile;
• and
• a charging gun, which comprises a charging resistor, a discharging resistor, and a second controllable switch circuit, wherein the second controllable switch circuit is configured to achieve switching between the charging resistor and the discharging resistor;
• wherein the control module is signal-connected to the first controllable switch circuit, the second controllable switch circuit, and the communication module, and the control module is configured to, in a state where the charging port is connected to the power grid and based on battery status information of the electric automobile,
• control the first controllable switch circuit to switch to be connected to the charging port and control the second controllable switch circuit to switch to be connected to the charging resistor, so that a charging loop is formed to enable the charging gun to output an alternating voltage or alternating current being matched with a battery of the electric automobile.