Method for constructing equivalent circuit model of lithium ion battery

Abstract

The invention provides a method for constructing an equivalent circuit model of a lithium ion battery. The method includes the steps that an initial equivalent circuit model of the lithium ion battery is selected and includes multiple unknown parameters; the lithium ion battery is selected and tested so that multiple sets of test data can be obtained; Ohm internal resistance of the initial equivalent circuit model and equivalent capacitance of open-circuit voltage are obtained according to each set of test data; a simulation model of the initial equivalent circuit model is constructed, each set of test data is input into the simulation model, and initial values of the unknown parameters are set; estimation is performed on the unknown parameters through the simulation model and an optimization toolbox, and the estimation is stopped when an error between output voltage of the simulation model and output voltage in each set of test data meets a preset condition so that final values of the unknown parameters can be obtained. The embodiment of the method has the advantages that the equivalent circuit model is rapid to construct, and model constructing complexity is low.

Description

technical field [0001] The invention relates to the technical field of automobile manufacturing, in particular to a method for constructing an equivalent circuit model of a lithium-ion battery. Background technique [0002] Currently, lithium-ion batteries are a good power source for pure electric vehicles and hybrid vehicles. The establishment of a lithium-ion battery model is an essential part of electric vehicle simulation research, because the battery model can be used to estimate the important parameters of the battery SOC (state of charge) and terminal voltage. Therefore, establishing a lithium-ion battery model is of great significance for the research of pure electric vehicles and hybrid vehicles. [0003] For the lithium-ion battery model, the battery equivalent circuit model is the most widely used. At present, the equivalent circuit models of lithium batteries mainly include Rint model, Thevenin model and PNGV model. The modeling of these three models is to fir...

AI Technical Summary

Problems solved by technology

[0004] In the current modeling method, when the test data is obtained, the mathematical relationship between the output voltage and the input current in the lithium-ion battery equivalent circuit model is used for parameter identification, which makes the modeler need to select different equivalent circuits according to the Models are used to establish different mathematical relationships, and these mathematical relationships are often complex, which is a complicated step for the modeling process of the lithium-ion battery equivalent circuit model, which makes the modeling process of the lithium-ion battery equivalent circuit model complex and slow

Images