Control-oriented lithium battery thermal model establishing method

Abstract

The invention relates to a control-oriented lithium battery thermal model establishing method, and belongs to the technical field of battery management. The method comprises the following steps of S1,performing order reduction on second-order partial differential heat conduction equations of cylindrical and square lithium batteries based on a spectrum-Galerkin method, and establishing control-oriented thermal models of the cylindrical and square lithium batteries; S2, selecting a cylindrical lithium battery and a square lithium battery, performing dynamic working condition test on the cylindrical lithium battery and the square lithium battery, and establishing a dynamic working condition data set of the batteries; S3, selecting a group of typical dynamic working condition data, and identifying unknown parameters of the lithium battery thermal model offline based on an optimal parameter identification algorithm; and S4, verifying the model precision and the working condition adaptability of the thermal model by adopting other working condition data in the dynamic working condition data set. Compared with the prior art, the modeling technology has the advantages that the modeling technology is not limited by the geometrical shape of the battery, the established thermal model is efficient in calculation and globally optimal, and detailed temperature information in the battery canbe extracted.

Description

technical field [0001] The invention belongs to the technical field of battery management and relates to a control-oriented lithium battery thermal model establishment method. Background technique [0002] Lithium-ion batteries are widely used in the development of green transportation due to their advantages such as high specific power, large specific energy, no memory effect, low self-discharge rate and good charge and discharge characteristics. However, with the widespread use of lithium batteries, the thermal safety of lithium batteries has become increasingly prominent. Under some typical high-power working conditions, the temperature difference between the inside and outside of the battery may even exceed 10°C. If it is not monitored in time, it is easy to cause the battery temperature to be too high, and even trigger thermal runaway, which may cause fire, electrolyte leakage and other accidents. Moreover, the battery operating temperature has a strong correlation wit...

AI Technical Summary

Problems solved by technology

Existing control-oriented thermal models have shortcomings such as the model is too simplified and cannot accurately obtain the temperature distribution inside the battery or the model is not applicable to a wide range.

Although the design-oriented thermal model can accurately simulate the heat generation and heat transfer laws of the battery and the internal temperature distribution, it cannot be used for actual battery temperature monitoring due to the high computational complexity of the model

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