Battery Module Health Evaluation via Impedance Decomposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for evaluating the state of health of battery cells in a group battery are complex, expensive, and time-consuming, particularly due to the need for multiple impedance calculation units and complicated measurement processes.
Innovation Solution
A group battery configuration where N batteries are connected in series, with at least (N-1) batteries having label elements in parallel, allowing for the measurement of a composite impedance characteristic, decomposition into individual battery plots, and calculation of each battery's state of health using Cole-Cole plots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple impedance calculation units are used to evaluate each battery cell in a group battery, then the state of health of each battery cell can be evaluated, but the device complexity and cost increase significantly
Solution Approach 1:
The patent merges multiple impedance calculation units into a single shared unit. The single impedance calculation unit sequentially connects to multiple battery cells through a multiplexer, allowing one unit to perform the evaluation function for all cells rather than requiring separate units for each cell. This reduces device complexity while maintaining the capability to evaluate each cell's state of health.
Solution Approach 2:
The single impedance calculation unit is designed to be universal, capable of evaluating the state of health for any battery cell in the group by sequentially connecting to different cells. This multi-functional approach allows one unit to replace multiple specialized units, reducing overall system complexity while preserving measurement precision for each individual cell.
2Measurement precision
If multiple impedance calculation units are used to measure impedances of multiple batteries, then each battery's state of health can be evaluated, but the measurement process becomes time-consuming
Solution Approach 1:
The patent implements periodic action by having the single impedance calculation unit sequentially connect to and measure each battery cell in turn. Instead of simultaneous measurements requiring multiple units, the system performs periodic sequential measurements, where each cell is measured in a systematic sequence. This approach maintains measurement accuracy for each cell while optimizing the total measurement time through efficient sequential operation.
3Device complexity
If a simple battery module configuration is used without label elements, then the device complexity is reduced, but the ability to differentiate and evaluate individual battery characteristics is lost
Solution Approach 1:
The patent introduces label elements as intermediary components connected in parallel with individual battery cells. These label elements serve as mediators that provide distinctive impedance characteristics to each battery, enabling the single impedance calculation unit to differentiate and identify individual battery responses during sequential measurement. The label elements add minimal complexity while significantly enhancing the measurement capability to distinguish between batteries with similar characteristics.
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
Enables a simple and efficient evaluation of the state of health of multiple battery cells within a group battery, reducing complexity and cost while providing accurate health assessments.
Implementation Method 1
at least (N−1) of the batteries respectively include label elements each connected in parallel with the battery cell and configured such that respective impedance characteristics of the N batteries differ from one another
Implementation Method 2
a measurement unit configured to measure a first Cole-Cole plot as an impedance characteristic of the group battery
Data Source
AI summary
A battery module 1 includes a group battery 2 in which batteries 30 (31 to 33) are connected in series, and an assessment evaluation unit 3 configured to calculate respective states of health of battery cells 10, in which the group battery 2 includes label elements 20 respectively connected in parallel with the battery cells 10 and configured such that respective impedance characteristics of the batteries 30 differ from one another, and the assessment evaluation unit 3 includes a measurement unit 42 configured to measure a first Cole-Cole plot of the group battery 2, a first calculation unit 44 configured to decompose the first Cole-Cole plot into respective second Cole-Cole plots of the batteries 30, a second calculation unit 44 configured to calculate respective third Cole-Cole plots of the battery cells 10 from the second Cole-Cole plots, and a third calculation unit 45 configured to calculate respective states of the battery cells 10 from the third Cole-Cole plots.