Battery OCV Pattern Analysis for Degradation Acceleration Estimation
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Solution Overview
Problem
Existing battery state estimation methods only provide information on past degradation, failing to predict future battery performance or lifetime, and do not offer specific insights into degradation acceleration rates.
Innovation Solution
A battery state estimating apparatus that measures open circuit voltage and electric resistance fluctuations, calculates voltage and resistance change rates, and determines degradation acceleration degrees through pattern analysis, enabling accurate estimation of current and future battery degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If conventional battery state estimation methods are used, then the degradation degree can be determined, but specific information about degradation rate and future performance cannot be provided
Solution Approach 1:
The patent segments battery degradation information into multiple dimensions: voltage fluctuation rate, resistance fluctuation rate, and their combinations. By dividing the degradation assessment into separate measurable components, the system can provide specific degradation rate information rather than just overall degradation degree, thus resolving the contradiction between information completeness and measurement precision.
Solution Approach 2:
The patent introduces new parameters (voltage fluctuation rate, resistance fluctuation rate) to characterize battery degradation. By changing from traditional single-parameter degradation assessment to multi-parameter dynamic assessment, the system can provide specific degradation rate information and future performance predictions, resolving the information loss problem while maintaining measurement precision.
2Loss of information
If only past degradation data is measured, then the degradation degree can be calculated, but future battery performance and lifetime cannot be predicted
Solution Approach 1:
The patent performs preliminary actions by continuously monitoring voltage and resistance fluctuations during battery operation. By collecting and analyzing fluctuation rate data in advance, the system establishes degradation trends that enable future performance prediction, thus preventing loss of future performance information while extending the effective prediction time horizon.
Solution Approach 2:
The patent implements feedback mechanisms by comparing measured voltage and resistance fluctuations against reference values and previously stored fluctuation rate data. This feedback loop allows the system to continuously update degradation assessments and predict future battery performance, resolving the contradiction between information availability and prediction capability.
3Loss of information
If detailed degradation analysis is performed, then specific degradation rate information can be obtained, but the device complexity increases
Solution Approach 1:
The patent makes the battery management system multi-functional by using the same voltage and resistance measurement infrastructure to serve multiple purposes: monitoring battery state, calculating degradation degree, determining degradation rates, and predicting future performance. This universal approach provides detailed degradation information without proportionally increasing device complexity.
Solution Approach 2:
The patent enables the battery system to self-diagnose degradation by using its own operational data (voltage and resistance measurements during normal operation). The system processes its own fluctuation data to generate degradation assessments and predictions without requiring external specialized equipment, thus obtaining detailed degradation information while minimizing additional device complexity.
Data Source
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AI summary
A battery state estimating apparatus according to an embodiment of the present disclosure includes: a voltage measuring unit configured to measure a voltage of a battery cell and measure an open circuit voltage (OCV) of the battery cell whenever the measured voltage reaches a reference discharge voltage; and a control unit configured to receive the OCV measured by the voltage measuring unit, compare the received OCV with a pre-stored reference voltage to calculate a voltage fluctuation rate, determine a voltage increase and decrease pattern based on the calculated voltage fluctuation rate and pre-stored voltage fluctuation rate data, and determine a degradation acceleration degree of the battery cell according to the determined voltage increase and decrease pattern.