Battery Cell Rest-Voltage Fitting for Abnormality Detection
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Solution Overview
Problem
Existing battery diagnosis methods fail to detect abnormal behaviors in battery cells beyond overvoltage and undervoltage, leading to potential fires, as they do not account for defects other than top or bottom voltage issues.
Innovation Solution
A battery diagnosis device and method that measures and calculates the fitting voltage of a battery cell after charging and discharging, comparing it with actual measured voltage to detect abnormal behavior by simulating the voltage shape during rest.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional overvoltage and undervoltage diagnosis methods are used, then simple voltage threshold checking is implemented, but abnormal behaviors beyond top or bottom voltage issues cannot be detected
Solution Approach 1:
The patent transforms the diagnosis approach from simple voltage threshold checking to analyzing the shape characteristics of voltage curves during rest periods. By fitting exponential functions to voltage data and comparing shape parameters (amplitude, time constant) against reference values, the system detects abnormal behaviors such as internal short circuits that traditional methods miss, thereby improving both reliability and detection coverage simultaneously
2Measurement precision
If exponential function fitting is applied to voltage data, then accurate simulation of rest section voltage shape is achieved, but calculation complexity increases
Solution Approach 1:
The patent applies exponential function fitting only to specific sections of the voltage curve (rest sections after charging or discharging) rather than the entire voltage profile. This localized approach maintains high measurement precision for the critical rest period while minimizing calculation complexity by avoiding unnecessary computations during active charging/discharging phases
3Reliability
If continuous voltage monitoring during rest periods is performed, then abnormal behaviors are detected early, but energy consumption increases
Solution Approach 1:
The patent implements voltage monitoring specifically during rest periods when the battery is not actively charging or discharging, rather than continuous monitoring. By utilizing the natural rest periods that occur between charge/discharge cycles, the system achieves early detection of abnormal behaviors without requiring additional energy expenditure during active operation phases
Data Source
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AI summary
A battery diagnosis device according to an embodiment of the present invention includes a voltage measurement unit configured to measure a voltage of a battery cell, a fitting value calculation unit configured to calculate a fitting voltage of the battery cell in a rest section after charging and discharging of the battery cell, and a diagnosis unit configured to diagnose abnormality of the battery cell by comparing the measured voltage measured by the voltage measurement unit and the fitting voltage calculated by the fitting value calculation unit, with respect to the rest section of the battery cell.