A linkage protection and alarm circuit driven by bms high side

Abstract

The invention discloses a linkage protection and alarm circuit driven by a battery management system (BMS) high side. The linkage protection and alarm circuit comprises a main positive circuit unit, a main negative circuit unit and a controller circuit unit. Linkage control when short circuit occurs in a main positive relay and a main negative relay is achieved by a simple resistance voltage division detection circuit, an AND gate control circuit and a high-level pull down circuit, and a relay control circuit is monitored in real time; when short circuit occurs, the linkage protection and alarm circuit can be disconnected within shortest time, and the safety performance is high; moreover, a user also can detect a three-route gate pole output signal through a human-computer interaction interface to timely know the relay in which short circuit occurs, the function of timely warning can be achieved, and the workload of maintenance is reduced.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a linkage protection and alarm circuit driven by a BMS high side. Background technique [0002] With the popularity of new energy vehicles, the safety performance of new energy vehicles has attracted more and more attention. When the main positive and negative relays on-board electric vehicles use high-side drive, when the high-side drive switch needs to be disconnected, the relay cannot be disconnected due to a sudden short circuit to the power supply. In non-emergency situations, it can be handled by software Solution, in an emergency, the control is given through software processing, and the disconnection time is much longer than our requirement. [0003] At present, the mainstream control scheme of the high-side drive of the electric vehicle BMS control relay is: 1. Select the high-side switch integrated chip with overvoltage, undervoltage, overcurrent, short circu...

AI Technical Summary

Problems solved by technology

However, switching off the high-side switch does not cut off the control loop in case of a short circuit to the power supply (such as figure 1 ), it still cannot be disconnected. At this time, software is still needed to disconnect other relays in the main circuit to unload the power

The third solution uses high-side drive and low-side drive two switches to control a relay. Due to the large number of relays in the BMS, this leads to a large number of high-side switches and low-side switches, which increases the cost. Similarly, based on safety The principle of power-off, when a switch is turned off, it is also necessary to diagnose the circuit to determine whether the power-off is successful. If the power-off is not successful, then turn off another switch, that is, to add a redundant switch, which requires software to control and turn off the power. longer time

This kind of protection method has been integrated in the high-side driver and low-side driver chip, which can realize the drive to turn off the high-side switch and the low-side switch. As a result, the high-side switch has been disconnected, but the load coil still cannot be disconnected. Open so that the relay cannot be disconnected

Images