Battery Cell SOC Mapping Across Temperature, Rate, and Voltage
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Solution Overview
Problem
Existing battery state of charge (SOC) estimation methods in battery management systems (BMS) lack accuracy and do not evaluate each battery cell individually, leading to inaccurate overall system evaluation.
Innovation Solution
A method that involves acquiring charging-discharging data of a first battery cell pack at different temperatures and rates, establishing an association table of SOCs with temperatures, rates, and voltages, and using this table to accurately estimate the SOC of each battery cell in a battery pack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If existing SOC estimation algorithms (data-driven method, Kalman filtering method) are used to perform overall evaluation on battery system, then the evaluation process is simplified, but the accuracy of SOC evaluation deteriorates because individual battery cell evaluation is not performed
Solution Approach 1:
The patent divides the battery system into individual battery cell units for separate evaluation. Instead of treating the battery system as a whole, the method segments the evaluation process to analyze each battery cell's charging-discharging characteristics independently, thereby improving SOC estimation accuracy while maintaining manageable complexity through modular data collection and analysis
2Measurement precision
If charging-discharging data is collected at multiple different temperatures and rates to establish comprehensive association table, then the accuracy of SOC estimation is improved, but the data collection complexity and time consumption increase
Solution Approach 1:
The patent performs preliminary data collection at multiple temperatures and rates during the association table establishment phase. By pre-collecting comprehensive charging-discharging data across various conditions and pre-establishing the association table beforehand, the system avoids time-consuming multi-condition testing during actual SOC estimation operations, thus reducing real-time evaluation time while maintaining high accuracy
Data Source
AI summary
The present application provides a battery SOC evaluation method, an apparatus, a device and a medium. The method includes: acquiring charging-discharging data of a first battery cell pack at different first temperatures and different first rates, where the number of the first battery cell pack is at least one, and the first battery cell pack includes a first battery cell; acquiring first SOCs of the first battery cell pack according to the charging-discharging data, where the charging-discharging data includes first voltages of the first battery cell pack; establishing an association table of the first SOCs with the first temperatures, the first rates and the first voltages; acquiring a second temperature, a second rate and a second voltage of a battery pack, and acquiring a second SOC of each second battery cell in the battery pack by the association table, where the battery pack includes multiple second battery cells.