A battery state of health assessment method

Abstract

The invention discloses a battery health status evaluation method, comprising the steps of: performing a charge and discharge test on the battery, and recording test data; performing data processing on the test data to obtain a V-dQ / dV data point set and performing filtering and noise reduction; identifying the data After the peak value of the point set is segmented according to the peak point, and then polynomial regression is performed on each segment of V‑dQ / dV to obtain the IC curve for qualitative analysis of the battery decay mode; the IC curve is integrated and then converted to obtain the Q‑V curve numerical model, and carried out Data verification, quantitative analysis of battery decay behavior by calculating the optimal voltage curve reconstruction model parameters. This method performs filtering and nonlinear regression operations on the test data and calculation results, which reduces the impact of measurement noise on the analysis results. It has strong adaptability and is suitable for various types of lithium-ion battery systems. It can qualitatively and quantitatively affect battery attenuation. Mode analysis, quantitative analysis can set a reasonable independent variable step size, greatly reducing the amount of calculation. The invention also proposes a battery health status evaluation system.

Description

technical field [0001] The invention belongs to the technical field of battery health status evaluation, and in particular relates to a battery health status evaluation method and evaluation system. Background technique [0002] With the aggravation of energy shortage and environmental crisis, the search for renewable energy to replace fossil fuels has become the focus of attention all over the world. Chemical batteries for energy storage have been widely used in consumer electronics, new energy vehicles, large-scale energy storage power stations and other fields. [0003] Electrochemical power sources such as lithium-ion batteries will gradually age with the battery during use, manifested as capacity attenuation, power loss, etc., until the functional requirements specified when the battery leaves the factory are lost. In order to ensure the stable and reliable operation of the battery system, it is necessary to accurately evaluate the health status and attenuation degree ...

AI Technical Summary

Problems solved by technology

However, since the voltage curve characteristics of different types of batteries are very different, and the capacity of the battery will decay as the number of cycles increases, and the voltage curve will also be deformed, making the method of empirical formula fitting poor in adaptability and reliability

[0008] The Chinese invention patent application and document (J Cleaner Production, 2018, 193-379) with the publication number CN103576097B introduces a method based on the balance potential curve of positive and negative electrodes, using genetic algorithm, particle swarm algorithm and other algorithms to reconstruct the full battery voltage curve , to obtain a set of optimal key parameters, and then evaluate the battery attenuation mechanism, and obtain the attenuation value of the internal components of the battery. However, in the calculation process of this method, the test data is not preprocessed, but the error corresponding to each test data point is required , the amount of calculation is large, and if the points are taken at intervals in the test data, the influence of noise cannot be avoided

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