Secondary Battery Parameter Estimation via Internal Resistance Comparison
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Solution Overview
Problem
Existing secondary battery parameter estimation methods using equivalent circuit models face challenges in securing accuracy due to the complexity of chemical reactions, leading to uncertainties in parameter estimation.
Innovation Solution
A secondary battery parameter estimation device and method that includes a voltage acquisition unit, current acquisition unit, parameter estimation unit, internal resistance deriving unit, and determination unit, which estimate and derive internal resistance using different methods and compare results to determine parameter accuracy and potential replacement, considering factors like switching events, full charge capacity, state of charge, and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If parameter estimation is performed using an equivalent circuit model, then parameter estimation can be implemented, but accuracy cannot be secured due to the complexity of chemical reactions
Solution Approach 1:
The patent introduces an internal resistance derivation unit that uses a different method (intermediary approach) to derive internal resistance compared to the parameter estimation unit. This intermediary derivation method serves as a mediator to verify and improve the accuracy of parameter estimation results by comparing against independently derived values
Solution Approach 2:
The determination unit compares the internally derived resistance with the parameter estimation result and provides feedback on whether to replace the estimated parameters. This feedback mechanism allows the system to self-correct and improve accuracy by validating estimation results against independently derived values
2Productivity
If parameters are estimated in predetermined cycles, then parameters can be updated, but timely updates may be missed during switching events
Solution Approach 1:
The patent implements a dynamic parameter update mechanism that adapts the estimation timing based on battery operating conditions. The determination unit dynamically decides whether to replace parameters by comparing derived resistance with estimated resistance, allowing updates to occur at appropriate moments rather than rigid predetermined cycles
Solution Approach 2:
The system performs preliminary derivation of internal resistance using a different method before making the determination to replace parameters. This preliminary action ensures that accurate reference values are prepared in advance for comparison, enabling timely and accurate parameter updates during switching events
Data Source
AI summary
A parameter estimation device includes: a voltage acquisition unit; a current acquisition unit; a parameter estimation unit; an internal resistance deriving unit; and a determination unit configured to determine, on the basis of a result of comparison between the internal resistance estimated by the parameter estimation unit and the internal resistance derived by the internal resistance deriving unit, whether or not to replace parameters of the secondary battery with the plurality of parameters estimated by the parameter estimation unit.