Control method for keeping safe state during abnormal reset of BMS (Battery Management System)

Abstract

The invention relates to a control method for keeping a safe state during abnormal reset of a BMS (Battery Management System). The method comprises the following steps: before a latch obtains a new control command of a CPU, keeping an IO signal output by the latch unchanged; and starting a BMS for self-checking, and controlling the CPU to send a new control command to the latch according to the self-checking result, so that the safety state of the vehicle is further ensured. The latch communicating through an SPI can keep the output IO signal when the CPU is reset abnormally, then the state of a high-voltage loop is kept, and then the BMS enters a proper safety state through a control method after the CPU is abnormally reset, so that the BMS system does not have the problem of high voltage drop caused by the abnormal reset of the CPU in the running process of the whole vehicle, and the functional safety of the whole vehicle is ensured.

Description

technical field [0001] The invention belongs to the field of battery management systems for new energy vehicles, in particular to the field of methods for maintaining a safe state when the BMS is abnormally reset. Background technique [0002] As one of the core components of electric vehicles, the Battery Management System (BMS) has always been the focus of electric vehicle research and development; BMS, as a very important function of the new energy vehicle power battery management system, is through the high-side switch or low-side switch. Control the relay on and off of the high-voltage circuit to realize the charging and discharging of the power battery. Generally, an IO port of the CPU is used to drive the high-side switch or low-side switch circuit. When the IO of the CPU is set to 0, the high-side or low-side output disconnects the relay. Signal, if the IO of the CPU is 1, the high-side or low-side outputs a closed relay signal, and the initialization state of the hi...

AI Technical Summary

Problems solved by technology

[0002] Battery Management System (BMS), as one of the core components of electric vehicles, has always been the focus of electric vehicle research and development; BMS, as a very important function of the power battery management system of new energy vehicles, is through the high-side switch or low-side switch Control the on-off of the high-voltage circuit relay to realize the charging and discharging of the power battery. Generally, an IO port of the CPU is used to drive the high-side switch or low-side switch circuit. When the IO of the CPU is set to 0, the high-side or low-side output disconnects the relay. Signal, if the IO of the CPU is 1, the high-side or low-side outputs a closed relay signal, and the initialization state of the high-side or low-side drive IO is disconnected, and the discharge state of the power battery is the driving process of the whole vehicle. If the CPU is abnormally reset due to random failure during the driving process of the whole vehicle, the IO port of the CPU will also follow the reset to restore the initialization state value, that is, the disconnected state. At this time, there will be a phenomenon of sudden high voltage drop during the driving process of the whole vehicle; The working environment of the whole vehicle is different in thousands of ways, and it is inevitable that the CPU abnormal reset phenomenon may occur due to random failures. The existing methods and strategies for controlling the high-voltage circuit will cause the danger of high voltage loss after the CPU abnormal reset. In severe cases, it will cause casualties of the passengers, which seriously violates the safety of the drivers and passengers.

Images