Battery Charging Voltage Trend Detection for Thermal Runaway Prevention
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Solution Overview
Problem
The increasing occurrence of thermal runaway accidents in power batteries during charging, caused by internal short circuits, poses a risk to safety and requires effective control of the battery charging process to prevent such incidents.
Innovation Solution
A battery charging control method and device that monitors the voltage of N cell units over M sampling periods, calculating the battery voltage and fitting curves to determine if the voltage trend is non-rising, and stops charging when both conditions are met to prevent thermal runaway, considering both battery and cell unit voltage changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous monitoring of voltage is performed during charging, then safety is improved, but device complexity increases
Solution Approach 1:
The patent performs curve fitting on voltage data in advance to establish a normal charging voltage curve model. This preliminary action allows the system to compare actual voltage deviations against the pre-established model, enabling early detection of abnormal conditions without requiring complex real-time analysis algorithms during charging.
Solution Approach 2:
The patent implements a feedback mechanism where the actual voltage of cell units is continuously monitored and compared against the fitted voltage curve. When the deviation exceeds a threshold, the system provides feedback to stop charging. This feedback loop enables safety control through simple threshold comparison rather than complex real-time analysis.
2Measurement precision
If voltage monitoring of individual cell units is implemented, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the battery into N individual cell units and monitors the voltage of each cell unit separately. By segmenting the monitoring task at the cell level, the system achieves precise measurement of individual cell voltages while using a standardized monitoring approach for each cell, avoiding the need for complex centralized analysis.
Solution Approach 2:
The patent transforms the complex problem of real-time voltage analysis by changing the parameter representation - instead of analyzing raw voltage data directly, it fits the voltage data to a curve and analyzes deviations from the fitted curve. This parameter transformation simplifies the detection of abnormal voltage trends.
3Reliability
If charging is stopped based on voltage trends, then reliability is improved, but productivity decreases
Solution Approach 1:
The patent replaces traditional mechanical or simple threshold-based charging control with a data-driven approach using curve fitting and statistical analysis of voltage trends. This substitution enables more intelligent decision-making that can distinguish between normal voltage fluctuations and genuine safety threats, reducing unnecessary charging interruptions.
Solution Approach 2:
The patent monitors voltage trends over M sampling periods and only stops charging when the deviation threshold is exceeded by a significant margin. This partial action approach - not stopping at the first sign of minor deviation but requiring excessive deviation - prevents premature charging termination while maintaining safety.
Data Source
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AI summary
This application provides a battery charging control method and device. Voltages of N cells in an Mth sampling period are obtained, and a voltage of the battery at each sampling moment among K sampling moments in said sampling period is calculated. Charging of the battery is stopped when the voltage of the battery increases monotonically in the Mth sampling period and a trend of a fitting curve of the voltage of at least one cell among the N cells in said sampling period is not rising.