Multi-time-scale square lithium battery SOC and SOT joint estimation method

Abstract

The invention relates to a multi-time-scale square lithium battery SOC and SOT joint estimation method, and belongs to the technical field of battery management. The method is realized on the basis ofa control-oriented square lithium battery electro-thermal coupling model in combination with an advanced multi-time scale estimation algorithm. The method comprises the following steps of determiningheat production related parameters in an electric model in advance through experiments, acquiring other parameters of the electric model through online parameter identification, and then achieving SOC estimation at the current moment in combination with an observer; according to the SOC and the temperature value of the previous moment, determining the heat production rate of each discrete volumeunit of the battery, and obtaining the temperature distribution of the current moment; and then updating electric model parameters by utilizing the current temperature and the SOC value, determining the heat production rate of the discrete volume unit, and iteratively updating the SOC value and the SOT value in this way. The estimation precision and the calculation resource utilization condition can be well balanced, and strong-robustness, high-fault-tolerance, accurate and efficient lithium battery electric heating characteristic monitoring under different time scales is realized.

Description

technical field [0001] The invention belongs to the technical field of battery management, and relates to a joint estimation method of SOC and SOT of a square lithium battery with multiple time scales. Background technique [0002] At present, there have been many studies on the estimation of SOC or SOT of lithium batteries alone. Common SOC estimation methods are mainly ampere-hour integration method, open circuit voltage method, data-driven method, model-based method and some hybrid methods. Due to the ease of implementation, the ampere-hour integration method, the model-based method, and some simple hybrid methods, such as the combination of the ampere-hour integration method and the open-circuit voltage method, are widely used now. Common SOT estimation methods mainly include methods based on EIS measurements, methods based on simplified thermal models, methods based on data-driven methods, and methods combining EIS measurements and simplified thermal models. The curre...

AI Technical Summary

Problems solved by technology

However, for square lithium batteries, the assumption of uniform heat generation or concentrated heat source will introduce a large model error, which is not conducive to the capture and monitoring of the thermal characteristics of lithium batteries

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