Battery management system

Abstract

The invention relates to a battery management system which comprises a main controller (1) connected with an internal CAN bus (2) and more than one slave controller (3), wherein each slave controller is connected with a corresponding battery module (5) and a corresponding battery equalizer (4) pairwise; the main controller is also connected with an external CAN bus (6), and both the internal CAN bus and the external CAN bus comprise respective independent CAN communication modules. Furthermore, in the battery management system, the slave controllers and the battery equalizers are provided with independent interfaces connected with the battery modules, an independent AD sampling chip in each slave controller adopts an isolated DC-DC power supply, the communication between the independent AD sampling chips and a microprocessor is isolated by an optical coupler, the main controller monitors the current of a battery pack by using a double-range Hall current sensor. Thus, the structure of the management system is safe and reliable, interference among the AD sampling chip, the microprocessor and the battery equalizer is avoided, and the test requirement of current measurement under two different conditions is met.

Description

technical field [0001] The present invention relates to batteries and battery management, in particular to a battery management system especially applied to vehicle power management. Background technique [0002] The battery management system is the key to the application of power batteries and the development of the new energy vehicle industry. In electric vehicles, electric bicycles and electric motorcycles, the battery management system is responsible for collecting the data of the single cells (voltage, current and temperature) in the battery pack, estimating the working status of the battery pack, balancing the power of the single cells between the battery packs, Implement thermal management, battery system fault diagnosis and alarm, etc., and perform data communication with other components or systems on the vehicle. However, the existing battery management system has the following defects or deficiencies: [0003] (1) The safety requirements of the battery managemen...

AI Technical Summary

Problems solved by technology

[0005] (3) In the existing system, the sensor whose range meets the maximum charging and discharging current of the battery pack is used, resulting in inaccurate measurement data when the battery pack is charged and discharged with a small current, which cannot meet the requirements for accurate estimation of the system on chip (SOC), which is not conducive to hybrid vehicles optimal control of

[0006] (iv) In the existing system, the balance mode of resistance discharge type is adopted, and the balance circuit and the slave control module will be integrated and packaged together. On the one hand, this will waste precious electric energy, and on the other hand, due to poor heat dissipation conditions in the module, the temperature will Possibility of over-monitoring equalization failure

Or use the method of taking power from the battery pack and charging the battery with a lower capacity through a direct current (DC)-direct current (DC) converter, which has a complex structure and high cost

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