Intelligent lithium ion battery management system for electric vehicle and balance control method thereof

Abstract

The invention relates to an intelligent lithium ion battery management system for an electric vehicle. The management system is characterized in that a microcontroller module is connected with a power supply module, a data detection module, a charge-discharge control module, a safety protection module, a communication module, a data storage module and a balance management module. The balance control method comprises the following steps: carrying out balance self-inspection according to each collected single cell voltage data in a cell unit; if the balance self-inspection is successful, judging whether to start balance control; if the difference between the single cell voltage and the average value voltage is larger than a preset threshold voltage and the voltage of a certain single cell is larger than a preset threshold, carrying out balance control with PWM duty ratio obtained based on the single cell voltage being as balance time; or otherwise, giving up carrying out the balance control. The management system in the invention is a centralized battery management system, and has the advantages of small size, stable performance, high detection precision, low cost and high reliability and the like.

Description

technical field [0001] The invention belongs to the field of power battery management systems, in particular to a battery management system for lithium-ion power batteries. Background technique [0002] With the development of electric vehicles and hybrid power tools, various power batteries are widely used. Lithium batteries have become the most promising power batteries due to their small size, high energy density, long cycle life, and low self-discharge rate. However, the safety and stability of lithium batteries are not high, and overcharging and overdischarging will cause damage to lithium-ion batteries. Therefore, in order to ensure the safe operation of lithium-ion batteries, a high-performance battery management system must be equipped. [0003] Existing lithium-ion protection devices for electric vehicles mostly use lithium-ion battery protection boards to achieve some basic protection functions, have no storage function, have low balancing accuracy, and cannot pro...

AI Technical Summary

Problems solved by technology

However, the safety and stability of lithium batteries are not high, and overcharging and overdischarging will cause damage to lithium-ion batteries. Therefore, in order to ensure the safe operation of lithium-ion batteries, a high-performance battery management system must be equipped.

[0003] Existing lithium-ion protection devices for electric vehicles mostly use lithium-ion battery protection boards to achieve some basic protection functions, have no storage function, and the balance accuracy is not high, nor can they provide users with intuitive and comprehensive battery monitoring information

Even if the lithium battery management system is adopted, due to the high cost, large size and high power consumption of the existing lithium battery management system, it is difficult to apply it to electric vehicles with low cost and small capacity power batteries

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