Battery Impedance Profile Fitting for Noise-Robust Parameter Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery parameter estimation methods using electrochemical impedance spectroscopy (EIS) are prone to noise during measurement and calculation, leading to inaccurate estimation of parameters such as Ohmic resistance, charge transfer resistance, and double layer capacitance.
Innovation Solution
A battery parameter estimating apparatus and method that includes an impedance measuring unit to output AC currents, generate a first profile by fitting impedance values, correct these values based on a profile, determine criterion values, and set battery parameters through multiple verification steps using threshold comparisons and curve fitting algorithms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If EIS measurement and curve fitting are used to estimate battery parameters, then the parameters can be obtained for SOH estimation, but noise is introduced during measurement and calculation leading to reduced accuracy
Solution Approach 1:
The patent applies preliminary action by performing curve fitting to generate a reference profile before comparing actual impedance values against it. This pre-established baseline allows for systematic identification and correction of noisy measurements, improving the reliability of parameter estimation before final calculation.
Solution Approach 2:
The patent implements feedback by comparing measured impedance values against a fitted curve profile and using the deviation information to identify and correct noisy data points. This feedback mechanism continuously refines the measurement accuracy by leveraging the relationship between expected and actual values.
2Measurement precision
If multiple verification steps and curve fitting algorithms are implemented, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent segments the parameter estimation process into distinct stages: initial curve fitting to establish a profile, comparison of measured values against the profile, identification of outliers, and correction steps. This segmentation allows each stage to be optimized independently while maintaining overall system manageability.
Solution Approach 2:
The patent applies partial action by implementing verification and correction only for impedance values that deviate beyond a threshold from the fitted curve. Not all measurements undergo the full correction process, reducing computational overhead while maintaining accuracy for critical measurements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method achieves high accuracy and reliability in estimating battery parameters by minimizing noise and ensuring precise determination of Ohmic resistance, charge transfer resistance, and double layer capacitance, thereby improving the accuracy of State of Health (SOH) estimation.
Implementation Method 1
battery parameter estimating apparatus and method capable of estimating a parameter of a battery through electrochemical impedance spectroscopy (EIS)
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
A battery parameter estimating apparatus according to an embodiment of the present disclosure includes an impedance measuring unit configured to output a plurality of AC currents to a battery and measure a plurality of impedance values for the battery to correspond to the plurality of AC currents; and a control unit configured to generate a first profile by fitting the plurality of impedance values, correct the plurality of impedance values based on the first profile, determine a plurality of criterion values based on the plurality of impedance correction values, generate a second profile by fitting the determined plurality of criterion values, compare the plurality of impedance correction values with the second profile, and determine whether or not to set a battery parameter according to the comparison result.