Bidirectional charging and discharging circuit and system

The utility model relates to a two-way charging and discharging circuit and system. The core of the two-way charging and discharging circuit is composed of a charging mode circuit unit, a charging pile mode circuit unit, a circuit switching unit and a circuit detection unit. The circuit switching unit connects a CP signal line of a vehicle interface to the charging mode circuit unit, or connects a CC signal line and the CP signal line of the vehicle interface to the charging pile mode circuit unit; the circuit detection unit detects signals of the CC signal line and/or the CP signal line; when the CP signal line is connected to the charging mode circuit unit, charging connection confirmation is carried out according to signals of the CC signal line and the CP signal line so as to indicate the electric vehicle to charge the mobile energy storage system; and when the CC signal line and the CP signal line are connected to the charging pile mode circuit unit, the mobile energy storage system is indicated to charg