Local sensitivity analysis method of lithium ion battery

Abstract

The invention discloses a local sensitivity analysis method of a lithium ion battery. The local sensitivity analysis method comprises the following steps: S1, establishing a circuit equation of an equivalent circuit model in target lithium ion battery state-of-charge estimation according to the Kirchhoff law; S2, obtaining parameter values of circuit elements in the equivalent circuit model through an HPPC experiment; and S3, obtaining the local sensitivity of the circuit element parameters in the equivalent circuit model to the accuracy of the equivalent circuit model and the local sensitivity of the circuit element parameters to the estimation accuracy of the state of charge through a control variable method. The invention provides the unified, clear, definite and quantitative local sensitivity analysis method to measure the influence of parameter changes of different circuit elements in the equivalent circuit model on the accuracy of the model and the accuracy of SOC estimation.

Description

technical field [0001] The invention relates to the field of battery analysis, in particular to a local sensitivity analysis method of a lithium ion battery. Background technique [0002] Since the 21st century, people expect cars to be cleaner and more environmentally friendly, and electric vehicles have received widespread attention. Compared with traditional fuel vehicles, electric vehicles have no pollution, low noise, and excellent acceleration performance, and are favored by governments and consumers in various countries. Batteries are the core components of electric vehicles. A battery management system is essential for batteries. The most important function of the battery management system (battery management system, BMS) is to complete the estimation of the battery state of charge (State of Charge, SOC). [0003] In a variety of Li-ion battery SOC estimation algorithms, the equivalent circuit model is the basis for estimation. Commonly used equivalent circuit mo...

AI Technical Summary

Problems solved by technology

The biggest challenge faced in the SOC estimation method based on the equivalent circuit model is that the circuit element parameters have different values ​​in different situations, such as discharge rate, battery aging degree, different ambient temperature, etc.

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