Battery Cell Voltage History Analysis for Rest-Period Fault Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing battery management systems fail to accurately detect abnormalities in battery cells when voltage changes occur gradually over time, particularly during rest periods, leading to undetected defects.
Innovation Solution
A battery management apparatus and method that measures and compares the voltage history of each battery cell with a reference voltage at preset intervals during rest periods, determining abnormalities by analyzing the accumulated changes and thresholds in cell voltage behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If threshold-based voltage drop detection is used, then instantaneous abnormalities are detected, but gradual voltage changes during rest periods are not detected
Solution Approach 1:
The patent changes the detection parameter from instantaneous voltage drop to accumulated voltage change over time. By integrating voltage measurements over a rest period and comparing the accumulated change against a threshold, the system detects gradual abnormalities that instantaneous detection would miss, while maintaining the ability to flag significant deviations.
Solution Approach 2:
The system performs preliminary voltage measurements and accumulates changes during the rest period before making a definitive abnormality determination. This preliminary accumulation phase allows the system to capture gradual voltage changes that occur over time, enabling detection before the abnormality becomes critical.
2Reliability
If voltage monitoring is performed only during charging/discharging, then operational abnormalities are detected, but rest period abnormalities are missed
Solution Approach 1:
The monitoring system is designed to perform universally across different operational states - both during charging/discharging and during rest periods. The same voltage measurement and accumulation logic applies regardless of battery state, eliminating the need for separate monitoring systems for different operational modes and reducing overall system complexity.
Solution Approach 2:
The system implements periodic voltage monitoring that adapts to the battery's operational state. During rest periods, it performs accumulated voltage change detection at regular intervals, while during charging/discharging it performs instantaneous threshold detection. This periodic, state-adaptive approach ensures comprehensive coverage without requiring continuously complex monitoring logic.
3Measurement precision
If accumulated voltage change detection is used, then gradual abnormalities are detected, but instantaneous drops may be overshadowed
Solution Approach 1:
The detection system is segmented into two independent detection paths: one for instantaneous voltage drop detection and another for accumulated voltage change detection. Each path operates with its own threshold and logic, allowing both instantaneous and gradual abnormalities to be detected independently without one overshadowing the other. The results from both paths are then combined for comprehensive abnormality detection.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A battery management apparatus according to the present disclosure includes a voltage measurement circuit to measure a cell voltage of each of a plurality of battery cells; and a control unit to determine the cell voltage of each of the plurality of battery cells and a reference voltage of the plurality of battery cells at a preset time interval during a rest period. The control unit determines a first accumulated change of the cell voltage of each battery cell during the rest period. The control unit determines a second accumulated change of the reference voltage during the rest period. The control unit determines whether each battery cell is defective by comparing the first accumulated change of each battery cell with the second accumulated change.