Secondary Battery Abnormality Detection via Voltage-Current Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting abnormalities in secondary battery systems, such as sodium-sulfur batteries, face challenges in identifying the source of internal or external short circuits, which can lead to delayed responses due to gradual changes in electric discharge depth, making it difficult to pinpoint the affected module or block promptly.
Innovation Solution
An apparatus and method that utilize voltage measurement units, string current measurement units, and correlation determination units to identify abnormalities by detecting changes in block voltage and string current correlations, allowing for early detection of short circuits and accurate identification of the affected module, even in large systems where temporary voltage drops can be misinterpreted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage measurement and correlation analysis are implemented to detect short circuits, then detection precision is improved, but device complexity increases
Solution Approach 1:
The control device performs multiple functions including voltage measurement, correlation coefficient calculation, and abnormality detection using a single integrated system. The control device utilizes existing voltage measurement infrastructure while adding correlation analysis capabilities, allowing one device to serve multiple detection purposes without requiring separate dedicated equipment for each function.
Solution Approach 2:
The invention changes the parameter being analyzed from simple voltage magnitude to the correlation coefficient between voltage and current. This parameter transformation enables detection of short circuits that may not be apparent through voltage magnitude alone, improving detection precision while utilizing the same measurement hardware.
2Measurement precision
If detection is performed for each individual battery cell, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The invention merges the detection of multiple battery cells into a single correlation analysis performed on aggregate voltage and current measurements. Instead of individually monitoring each cell, the control device analyzes the correlation between overall voltage and current to detect short circuits, combining multiple detection tasks into one unified process that reduces system complexity.
3Reliability
If correlation-based detection is used to distinguish short circuits from temporary voltage drops, then reliability is improved, but loss of time increases due to calculation requirements
Solution Approach 1:
The control device continuously calculates and maintains the correlation coefficient between voltage and current as a baseline condition. This preliminary action ensures that when a short circuit occurs, the deviation from the established correlation pattern can be immediately detected without requiring time-consuming calculations at the moment of abnormality, thus improving reliability while minimizing detection delay.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention pertains to a device, method, and program for specifying an abnormality-occurrence area of a secondary battery system. The device has: an information acquisition unit (54) for acquiring information about a module (module information) from among a plurality of modules included in a module series that accommodates a block for which the difference between a block voltage value and a block voltage value after a primary delay has changed so as to exceed a voltage threshold within a preset time before and after the point in time at which the block voltage value and series current value stopped being correlated; a notification reception unit (56) for receiving a notification about the occurrence of an abnormality in a secondary battery; and a module specification unit (58) for specifying at least the module corresponding to the latest module information as the module in which an abnormality occurred when the notification reception unit (56) receives a notification.