Method for reconstructing open-circuit voltage-state of charge function relation of power battery

Abstract

The invention provides a method for reconstructing an open-circuit voltage-state of charge function relation of a power battery. According to the method, real vehicle acquisition data is divided according to a parking charging process in order to obtain data fragments, a battery model is established, and OCV values at all sampling points in each data fragment are identified, so that an OCV-SOC scattered point mapping relation fragment corresponding to each data fragment is established based on a preset SOC reference value. In an SOC-OCV coordinate system, the OCV-SOC scattered point mapping relation fragment with the highest OCV value is fixed, other OCV-SOC scattered point mapping relation fragments continuously carry out translation along an SOC axis direction, and the OCV-SOC scatteredpoint mapping relation fragments after translation are subjected to overall fitting until an optimal fitting effect is achieved, so that an optimal solution of splicing of the OCV-SOC scattered pointmapping relation fragments, namely an optimal OCV-SOC function relation is obtained. According to the method, a traditional time-consuming battery experiment is not needed, the OCV-SOC function relation can be directly reconstructed through the real vehicle acquisition data, the algorithm development period is greatly shortened, and the algorithm development cost is reduced.

Description

technical field [0001] The invention relates to the technical field of power battery management, in particular to a method for reconstructing the relationship between the open circuit voltage of a vehicle power battery and a state of charge function. Background technique [0002] The open circuit voltage (OCV)-state of charge (SOC) function relationship of the power battery establishes a stable mapping relationship between the battery state and the battery terminal voltage, which is extremely important for battery state estimation. At present, the OCV-SOC function relationship is mostly obtained through experimental methods. The acquisition of the OCV-SOC function relationship under the full life cycle of the power battery requires long-term battery aging experiments, which increases the development cycle and cost of the algorithm. [0003] With the promotion and networking of electric vehicles, a large amount of data collected from real vehicles is stored in the electric ve...

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Problems solved by technology

Therefore, relatively accurate SOC cannot be obtained from data fragments, and the traditional OCV-SOC function relationship identification method based on complete experimental data is difficult to directly apply

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