An online measurement system and method for cell capacity and health state of a lithium ion battery group

Abstract

The invention discloses a lithium ion battery management system and an online measurement method for cell capacity and health state of a battery electrical core. The system is composed of a master control unit, a cell sensing monitoring unit and an electric current sensor. High-low voltage separating design is adopted, and the cell sensing monitoring unit is used for monitoring and measuring the voltage of the battery electrical core monomer; the electric current sensor is used for measuring the busbar electric current of a major loop of the electric circuit; the master control unit is used for controlling the work mode of the lithium ion power battery group, processing and storing of data, and online-measuring the battery monomer electrical core capacity, on this basis, online diagnosis monitoring for the health state of the battery electrical core monomer is performed, reliable reference for the replacing of the battery electrical core is provided, the property and state of the lithium ion power battery group can be effectively monitored, important basis is provided for the calculating of other inner state parameters of the battery, important information is provided for the strategy of automobile, and the safety of the vehicle and the driver and passenger is guaranteed.

Description

technical field [0001] The invention relates to the measurement of battery parameters, in particular to a lithium-ion battery management system and a method for on-line measurement of battery cell capacity and health status judgment. Background technique [0002] At present, lithium-ion power batteries have been used on a large scale in new energy vehicles. Since the voltage, power, capacity, and energy of a lithium-ion battery cell cannot meet the actual application requirements, grouping technology must be used to connect multiple batteries in series to realize lithium-ion power battery packs and even new energy vehicles. car performance indicators. [0003] Capacity is one of the most important parameters of Li-ion batteries. Capacity refers to the total amount of charge that the battery cell can release to the outside. [0004] Capacity is the basis for defining the State of Charge (SOC) of lithium-ion batteries. SOC is generally defined as the percentage of current ...

AI Technical Summary

Problems solved by technology

[0021] Moreover, even if various difficulties are overcome to achieve the above-mentioned working conditions, for lithium-ion batteries, the use method that reaches the charging and discharging termination conditions may lead to a reduction in battery life.

[0022] Finally, this method is still an offline method. As mentioned in the appeal, it is unlikely to be carried out, and of course it cannot be used frequently. This will lead to capacity, health status, etc., which cannot be frequently measured and adjusted during user use.

As a result, it will bring negative effects on the accuracy of state parameters, life, etc.

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