Battery Rack Voltage Trend Analysis for Abnormal Cell Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing energy storage systems face safety risks due to abnormal battery cells causing thermal runaway and ignition, necessitating early detection methods to prevent fires.
Innovation Solution
An abnormal cell detection device and method that analyzes cell voltage values over rest periods, calculates difference values, applies statistical analysis and linear regression to identify potential abnormal cells, and performs cross-verification to reduce false detections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If voltage difference analysis is performed to detect abnormal cells, then detection capability is improved, but false detections increase due to normal voltage variations
Solution Approach 1:
The system performs preliminary actions by collecting voltage data over multiple rest periods before making an abnormal cell determination. It calculates cumulative voltage differences and evaluates trends across multiple time points (first rest period, second rest period, etc.) rather than relying on a single measurement, thereby reducing false detections caused by temporary voltage variations.
Solution Approach 2:
The system implements feedback mechanisms by continuously monitoring voltage differences across multiple rest periods and using this historical data to refine abnormal cell detection. It compares cumulative voltage differences against threshold values and uses the pattern recognition from multiple measurements to distinguish between normal variations and actual abnormalities, thereby improving reliability.
2Reliability
If multiple rest periods are monitored to reduce false detections, then detection reliability is improved, but detection time increases
Solution Approach 1:
The system applies partial action by monitoring a predetermined number of rest periods (not necessarily all possible periods) to achieve sufficient detection reliability. It uses a balanced approach where the number of monitored periods is optimized to provide adequate confidence in detection results while avoiding excessive time consumption, thus resolving the contradiction between reliability and time loss.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An abnormal cell detection device includes: a storage device that stores cell voltage values detected for each rest period after discharge from a battery bank including a plurality of battery racks; and a control device configured to determine a maximum cell voltage value and a first minimum cell voltage value in each battery rack for each rest period, to determine a first difference value between the maximum cell voltage value and the first minimum cell voltage value in each battery rack for each rest period, to select a target battery rack by statistically analyzing a change in the first difference value during a predetermined period, to determine a second difference value between an average cell voltage value and a second minimum cell voltage value in each battery module of the target battery rack for each rest period and to determine a battery module including an abnormal cell in the target battery rack based on the second difference value.