Power lithium battery state joint estimation method based on multi-dimensional coupling model

Abstract

The invention relates to a power lithium battery state joint estimation method based on a multi-dimensional coupling model, and belongs to the technical field of battery management. The method comprises the following steps: S1, building an electric model of a battery, and building a battery thermal model and an aging model on the basis of the electric model; S2, recognizing model parameters with test data; S3, building an electric-thermal-aging coupling model of the battery; S4, estimating battery SOC in real time on the basis of the coupling model with a control method based on a state spaceequation, meanwhile extracting a battery center temperature value in the thermal model to serve as a SOT estimation value, and estimating the battery SOH with a capacity calculating method; and S5, setting a corresponding coupling framework in order to finish the joint estimation of the SOC, SOT and SOH of the battery. Through adoption of the method, the battery temperature and capacity changes are updated in real time in the SOC estimating process, so that the SOC estimation accuracy can be is improved greatly, and the SOT and SOH estimation accuracy are improved.

Description

technical field [0001] The invention belongs to the technical field of battery management, and relates to a coupling model of electricity, heat and aging of a lithium battery and a joint estimation method for the state of charge, state of health and temperature of the battery. Background technique [0002] During the use of the battery, there are problems such as temperature changes and aging. These changes will affect the performance and safety performance of the battery. Therefore, considering all factors affecting the battery during use, the electric-thermal-aging Coupling model, on the basis of the coupling model, evaluate the battery in three states of SOC, SOT, and SOH, and obtain real-time information of the battery. The state estimation results are applied to the battery management system (Battery Management System, BMS) to participate in the energy management decision-making of electric vehicles. [0003] The coupling models used at this stage mainly include electr...

AI Technical Summary

Problems solved by technology

[0005] Compared with the existing technology, first of all, in terms of the coupling model of lithium-ion batteries, most studies only consider the influence of temperature on the battery, that is, the electric-thermal coupling model. During the long-term use of the battery, as the number of battery cycles increases, the battery Both internal resistance and capacity will decay, so it is necessary to consider the aging of the battery, establish a battery electric-thermal-aging coupling model, comprehensively consider the impact of temperature and internal resistance changes on the battery, and improve the accuracy of the model. One of the issues that needs to be addressed in terms of battery models

[0006] Secondly, in terms of state estimation research, most studies only consider the estimation of a single state, using a variety of intelligent optimization algorithms to improve the accuracy of state estimation, but in actual use, it is necessary to fully understand the battery condition

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