Relay protection circuit for bms

Abstract

The invention relates to the field of relay protection, and discloses a relay protection circuit for a BMS. The relay protection circuit for a BMS includes: a BMS battery, a shunt resistor, a current detection module, an AFE chip, an MCU control chip, a pre-discharging MOS module, a pre-charging MOS module, a relay and a relay control power supply. A positive terminal of the BMS battery is connected to a negative terminal of an external load. A negative terminal of the BMS battery is connected to one end of the shunt resistor. The other end of the shunt resistor is connected to the pre-discharging MOS module and the relay. The relay is connected to a positive terminal of the external load. The relay control power supply is connected in parallel with the relay. The pre-discharging MOS module is connected in series with the pre-charging MOS module. The predischarging MOS module and the pre-charging MOS module are connected in parallel with the relay. In embodiments of the invention, MOS transistors are used to control the relay to be on or off, which reduces a number of relays in a control process and lowers assembly complexity and production cost.