Battery Impedance Circuit Reconstruction Without Iterative Tuning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the internal state of secondary batteries, such as lithium-ion batteries in electric vehicles, require complex iterative adjustments of impedance models to match actual impedance characteristics, making it difficult to derive accurate current-carrying patterns for efficient energy use.
Innovation Solution
A battery characteristic reproduction device and method that extracts the smallest resistance value and differences between resistance values at various frequencies to configure an equivalent circuit, connecting these components in series to reproduce the battery's impedance characteristics, thereby improving energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If iterative adjustment of impedance model pattern and circuit configuration is performed to match actual impedance characteristics, then measurement precision of battery internal state is improved, but device complexity and calculation time increase significantly
Solution Approach 1:
The patent transforms the complex iterative adjustment problem into a direct parameter extraction process by changing from adjusting circuit patterns to extracting resistance values at specific frequencies. The impedance characteristics are reproduced by directly using measured resistance values at predetermined frequencies as parameters in the equivalent circuit, eliminating the need for iterative pattern adjustments while maintaining accuracy.
Solution Approach 2:
The patent extracts specific resistance values from the impedance characteristics at predetermined frequencies and uses these extracted parameters directly to construct the equivalent circuit. This extraction approach bypasses the complex iterative adjustment process by taking out the essential parameters needed for accurate reproduction without requiring full model optimization.
2Measurement precision
If multiple equivalent circuits are connected in multiple stages to represent positive and negative electrodes, then measurement precision of frequency characteristics is improved, but ease of operation and derivation of current-carrying patterns deteriorates
Solution Approach 1:
The patent simplifies the operation by changing from complex multi-stage circuit analysis to direct parameter extraction at specific frequencies. The equivalent circuit parameters are obtained by measuring resistance at predetermined frequencies, which directly provides the information needed for current-carrying pattern derivation without requiring complex multi-stage circuit manipulation.
Solution Approach 2:
The patent performs preliminary extraction of resistance values at predetermined frequencies before deriving current-carrying patterns. This preliminary action prepares the essential parameters in advance, making the subsequent derivation of current-carrying patterns straightforward and eliminating the need for complex real-time analysis of multi-stage circuits.
3Measurement precision
If optimum values of impedance model parameters are determined to match calculation results with actual frequency characteristics, then measurement precision is improved, but loss of time in iterative adjustment increases
Solution Approach 1:
The patent extracts the necessary parameter values directly from frequency characteristic measurements at predetermined frequencies, eliminating the iterative adjustment process. The resistance values obtained at specific frequencies are used directly as equivalent circuit parameters, achieving accurate matching between calculation and measurement without time-consuming iteration.
Solution Approach 2:
The patent creates a simplified equivalent circuit that copies the essential impedance characteristics by using resistance values measured at predetermined frequencies. This copying approach reproduces the frequency characteristics accurately without requiring complex iterative optimization, as the measured values directly represent the circuit behavior at those frequencies.
Data Source
AI summary
A battery characteristic reproduction device includes a processor configured to execute computer-readable instructions to perform. The processor is configured to extracting a smallest resistance value included in frequency characteristics of measured impedance of a battery, extracting a difference between a resistance value measured at a measurement point and a resistance value measured at an adjacent measurement point for each measurement point of each frequency included in the frequency characteristics, and reproducing the frequency characteristics of the impedance in the battery by configuring the smallest resistance value extracted as a first resistance component, configuring an equivalent circuit of the battery including the difference between the resistance values extracted as a second resistance component for each measurement point, and connecting the first resistance component and the equivalent circuit for each measurement point in series.