Battery Cell Group Monitoring for Internal Short Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rechargeable energy storage systems (RESS) are vulnerable to internal short circuits, which can lead to excess heat and potential thermal runaway, necessitating early detection and mitigation to prevent damage.
Innovation Solution
A method involving a processor-controlled system that monitors cell groups for decreasing resistance and voltage deviations, differentiates between internal short circuits and overcurrent protection element fatigue, and adjusts operations to prevent damage by cooling, discharging, or modifying charging and discharging limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional monitoring methods are used, then device complexity is reduced, but measurement precision of internal short circuit detection deteriorates
Solution Approach 1:
The system divides the battery pack into multiple cell groups with parallel-connected cells, allowing independent monitoring of each group. This segmentation enables precise detection of individual cell failures without requiring complex monitoring of the entire battery system, as each cell group can be analyzed separately for resistance changes and voltage deviations.
Solution Approach 2:
The system continuously monitors resistance rates of change and voltage deviations as preliminary indicators before thermal runaway occurs. By detecting decreasing resistance rates and voltage anomalies early in the failure process, the system can identify internal short circuits before they lead to catastrophic heating, enabling preventive action rather than reactive response.
2Reliability
If early detection of internal short circuits is implemented, then reliability of RESS is improved, but loss of time for diagnosis and response increases
Solution Approach 1:
The system implements continuous feedback monitoring of resistance rates and voltage deviations across all cell groups. When a cell group exhibits a decreasing resistance rate of change combined with voltage deviation, the system immediately triggers a diagnostic routine that analyzes the specific pattern to confirm internal short circuit conditions, providing rapid feedback without requiring lengthy diagnostic procedures.
Solution Approach 2:
The system replaces complex mechanical or manual diagnostic procedures with electronic analysis of electrical parameters (resistance rate of change and voltage deviation). This substitution enables automated, rapid detection and diagnosis of internal short circuits through processor-based analysis of sensor data, significantly reducing the time required for accurate identification compared to traditional inspection methods.
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
Effectively detects and mitigates internal short circuits, thereby preventing damage to the RESS by accurately identifying and addressing the underlying performance, thereby enhancing the system's reliability and reducing the likelihood of thermal runaway, thereby enhancing the reliability and safety of the RESS.
Implementation Method 1
determining, via the processor, whether a cell group has a decreasing resistance rate of change
Implementation Method 2
determining, via the processor, whether the cell group has a sufficient voltage deviation indicative of an internal short circuit condition
Implementation Method 3
modifying operation of the device to prevent damage to the RESS includes cooling the RESS
Data Source
AI summary
A method includes operating a device having a rechargeable energy storage system (RESS) including parallel groups of cells having overcurrent protection elements, by passing a current through the cells based on instructions provided by a processor; obtaining sensor data via sensors; determining, via the processor, whether a cell group has a decreasing resistance rate of change; when the cell group has a decreasing resistance rate of change, determining, via the processor, whether the cell group has a sufficient voltage deviation indicative of an internal short circuit condition; when the cell group does not, determining, via the processor, whether the cell group has a voltage rate of change unrelated to the current; and when the cell group has a voltage rate of change unrelated to the current, concluding, via the processor, that an internal short circuit exists and modifying operation of the device to prevent damage to the RESS.