Battery Cell Balancing Abort Mechanism for Over-Balancing Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electric vehicle batteries, cell balancing is challenging due to manufacturing variances and differing charge/discharge histories, leading to inefficiencies and reduced longevity, as existing methods fail to effectively manage state of charge (SOC) differences and balancing times.
Innovation Solution
A processor-based system that detects SOC differences between cells and calculates a balancing time threshold, aborting the balancing process if it exceeds this threshold, and generates an error message to prevent over-balancing and potential system failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cell balancing is performed to maximize battery capacity and longevity, then battery performance is improved, but the system may experience over-balancing and potential failures if balancing time is not properly controlled
Solution Approach 1:
The system pre-calculates the expected balancing time before initiating the balancing operation by determining the SOC difference between cells and using it to compute a time threshold. This preliminary calculation allows the system to prepare safety parameters in advance, enabling proactive prevention of over-balancing before it occurs.
Solution Approach 2:
The system continuously monitors the actual balancing time during the balancing operation and compares it against the pre-calculated threshold. This feedback mechanism enables real-time detection of abnormal balancing conditions, allowing the system to abort the operation if the threshold is exceeded, thus preventing over-balancing and ensuring battery safety.
2Productivity
If balancing operation continues without time monitoring, then complete balancing may be achieved, but system failures may occur due to excessive balancing duration
Solution Approach 1:
The system pre-calculates the expected balancing time before initiating the balancing operation by determining the SOC difference between cells and using it to compute a time threshold. This preliminary calculation allows the system to prepare safety parameters in advance, enabling proactive prevention of over-balancing before it occurs.
Solution Approach 2:
The system continuously monitors the actual balancing time during the balancing operation and compares it against the pre-calculated threshold. This feedback mechanism enables real-time detection of abnormal balancing conditions, allowing the system to abort the operation if the threshold is exceeded, thus preventing over-balancing and ensuring battery safety.
3Reliability
If balancing is performed on cells with large SOC differences, then capacity optimization is improved, but balancing time increases beyond acceptable thresholds
Solution Approach 1:
The system pre-calculates the expected balancing time before initiating the balancing operation by determining the SOC difference between cells and using it to compute a time threshold. This preliminary calculation allows the system to prepare safety parameters in advance, enabling proactive prevention of over-balancing before it occurs.
Solution Approach 2:
The balancing time threshold is dynamically determined based on the actual SOC difference between cells. By using the measured SOC difference to calculate a customized time threshold, the system adapts the balancing parameters to the specific state of the battery cells, optimizing both the effectiveness and duration of the balancing operation.
Data Source
AI summary
A system comprises a processor, configured to perform balancing on a commanded cell referring to a reference cell, and responsive to detecting balancing time exceeding a threshold time and state of charge (SOC) difference being above a tolerance, abort the balancing, and generate an error message. The threshold time depends on an average balancing time calculated using the SOC difference, a predetermined commanded cell capacity, and a predetermined balancing current.