Static SOC estimation method based on dichotomy iteration

Abstract

The invention relates to a static SOC estimation method based on dichotomy iteration, and belongs to the field of new energy measurement and control; according to the method, an approximation iteration method is obtained according to a dichotomy theory, and intermediate value comparison processing is carried out by continuously reducing the interval, so that the effective estimation of the staticSOC value of a lithium ion battery is realized; a fitting polynomial is obtained directly by the lithium ion battery via an OCV-SOC curve, so that transformation or approximation processing is avoided, and the system processing error is reduced to the maximum extent; according to the method, the OCV approximation error range is set, so that the SOC error can be manually adjusted, and the controllable precision is realized; the method is low in algorithm complexity, the number of iterations is small, the response speed is high, the function similar to a universal meter can be realized, and thestatic SOC can be directly measured from the outside; on the basis of a traditional table look-up method and an interpolation method, and the method is improved to be a method for directly utilizing characteristic fitting expression calculation, so that the precision is improved, the pre-data processing work is reduced, and the operation capacity requirements of the processing unit are reduced, the static SOC of the lithium ion battery can be effectively measured and calculated.

Description

technical field [0001] The invention relates to a static SOC estimation method based on dichotomy iteration, belongs to the field of new energy measurement and control, and is a lithium ion battery estimation method based on mathematical function equation theory. Background technique [0002] Due to its high specific energy and small size, lithium-ion batteries have a great role in promoting environmentally friendly power applications. At present, they are widely used in the fields of automobiles, aerospace and portable electronic products, and in battery management. The core technology in the system (Battery Management System, BMS) is the estimation of the state of charge (SOC) of lithium-ion batteries, which is also a bottleneck technology affecting the development of new energy fields; finding and creating accurate estimation methods for SOC On this basis, ensuring the working performance of lithium-ion battery packs is a key issue that needs to be solved urgently. A lot...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to overcome the shortcomings of the existing open-circuit voltage estimation static SOC method, provide a method based on dichotomous iterative approximation, and solve the problem of accurate estimation of static SOC value in lithium-ion battery applications

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