Method of reconstructing OCV-SOC function relation of power battery system

Abstract

The invention provides a method of reconstructing the OCV-SOC function relation of a power battery system. The OCV-SOC function relation can be acquired quickly and effectively. Compared with the traditional open-circuit voltage test method, a lot of test time is saved, and the method is suitable for various different power batteries including lithium iron phosphate batteries and is more universal. Moreover, the OCV-SOC function relation correction role can be better ensured, and the robustness of the state estimation algorithm can be improved.

Description

Technical field [0001] The invention relates to the technical field of power battery system management, in particular to the acquisition of the function relationship between the open circuit voltage of the power battery system and the state of charge, battery modeling, and battery state estimation techniques. Background technique [0002] At present, model-based state estimation algorithms often use the open circuit voltage (OCV)-state of charge (SOC) function relationship to modify the SOC of the battery. Although the OCV-SOC function relationship is mostly obtained by the open circuit voltage test, it is still due to the open circuit voltage test. Time is difficult to control, too long static time will easily lead to too long test period, too short static time will make the battery stand insufficiently, which will cause a large error in the obtained OCV-SOC function relationship. More importantly, for power batteries such as lithium iron phosphate batteries, the OCV-SOC functio...

AI Technical Summary

Problems solved by technology

[0002] At present, model-based state estimation algorithms often use the open circuit voltage (OCV)-state of charge (SOC) function relationship to correct the SOC of the battery. Time is difficult to control, too long rest time will easily lead to too long test cycle, and too short rest time will make the battery stand insufficiently, resulting in a large error in the obtained OCV-SOC function relationship

More importantly, for power batteries such as lithium iron phosphate lithium-ion batteries, the OCV-SOC function relationship obtained from the open circuit voltage test has a long voltage plateau. When the SOC value is corrected using the OCV-SOC function relationship, it will lead to State estimation algorithm error increases or even diverges

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