Lithium ion battery remaining capacity estimation method

Abstract

The invention discloses a method for estimating the remaining capacity of a lithium ion battery. The method comprises the following steps: 1, establishing a fractional order model of the lithium ion battery; 2, performing parameter identification on parameters in the fractional order model; 3, establishing a state equation and an observation equation according to the fractional order model; 4, discretizing the state equation and the observation equation, and establishing a discrete state equation and a discrete observation equation which take the SOC as a state variable; 5, establishing an interactive multi-fractional-order model of the lithium ion battery; and 6, continuously estimating the residual electric quantity of the lithium ion battery. According to the method, a plurality of fractional order models representing different battery life states are established, the target state is adaptively tracked by using the interactive multi-model algorithm, the problem that the estimation precision is influenced by parameter change caused by battery aging can be avoided, the complexity of the model and the algorithm is reduced, the dynamic adaptability to the lithium ion battery is good, the estimation precision is high, and the method is suitable for large-scale popularization and application. The effect is obvious and popularization is convenient.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a method for estimating the remaining power of a lithium-ion battery. Background technique [0002] Battery state of charge (SOC), also known as battery remaining capacity, is an important indicator of lithium-ion batteries, generally defined as the ratio of battery remaining capacity to nominal capacity. For the estimation of lithium-ion battery SOC, a lot of resources have been invested in algorithm research at home and abroad, and good estimation results have been achieved. However, there are still some problems in the existing SOC estimation methods, so the research on SOC estimation algorithms is still a current research hotspot. Commonly used lithium-ion battery SOC estimation methods include ampere-hour integral method, open circuit voltage method, neural network method, and model-based methods. [0003] In the early stage of lithium-ion battery...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a method for estimating the remaining power of lithium-ion batteries in view of the deficiencies in the above-mentioned prior art. The method has simple steps, reasonable design, and convenient implementation; Compared with the estimation method of a single model, in terms of adapting to the battery aging state, multiple fractional-order models representing different battery life states are established, and the interactive multi-model algorithm is used to adaptively track the target state, which can avoid parameter changes caused by battery aging and thus The problem that affects the estimation accuracy reduces the complexity of the model and algorithm, improves the adaptability of the model, and effectively improves the ability of model aging evolution

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