Lithium battery state-of-charge estimation method based on high-rate discharge

Abstract

The invention discloses a lithium battery state-of-charge estimation method based on high-rate discharge. The method comprises the following steps: constructing a circuit equivalent model of an energystorage lithium battery; updating parameters of the circuit equivalent model in real time by adopting a recursive least square method; establishing a state equation and an observation equation of theenergy storage lithium battery; and estimating the state of charge of the lithium battery by adopting a quadratic root volume Kalman filtering algorithm. The lithium battery state-of-charge estimation method based on high-rate discharge aims to establish an energy storage battery equivalent circuit model capable of updating parameters in real time through a recursive least square method, and accurately estimate the state-of-charge of a lithium battery in combination with a quadratic root volume Kalman filtering algorithm. According to the method, the state of charge of the lithium battery can be accurately estimated under the condition of high-rate discharge, and the method is scientific, reasonable and high in reliability.

Description

technical field [0001] The invention belongs to the field of batteries, and in particular relates to a method for estimating the state of charge of a lithium battery based on high-rate discharge. Background technique [0002] With the development of economy and technology, electric energy has become an indispensable secondary energy source in people's production and life, bringing endless convenience to people's production and life. [0003] Lithium-ion batteries have the advantages of good safety, long life, and high power density, and are an excellent choice for energy storage systems. In practical engineering applications, in order to meet the requirements of energy storage systems in terms of voltage, current and power, it is often necessary to use a large number of single batteries in series and parallel combinations. Therefore, in order to be able to grasp the status of single cells and battery packs in real time and prevent overcharge, overdischarge, overtemperature,...

AI Technical Summary

Problems solved by technology

Under such extreme working conditions, the chemical reaction, temperature field and internal resistance inside the battery will change greatly. For example, the larger the discharge rate of the battery, the more uneven the temperature distribution inside the battery; when the battery is discharged at a high rate, The decomposition rate of the solid electrolyte interface is greater than the generation rate, and the internal resistance of the battery will decrease. Some changes will cause large fluctuations in the parameters of the battery model, making it very difficult to establish an accurate battery model.

These difficulties make current lithium battery state-of-charge estimation

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