Battery Contactor Disconnect Sequencing Based on Current and Health
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Solution Overview
Problem
The frequent mechanical and electrical wear of contactors in energy storage systems of vehicles leads to premature contactor failure, resulting in increased maintenance costs and reduced system reliability.
Innovation Solution
A computer system with processing circuitry is used to determine the measured current and health level of each contactor in a switching arrangement of an energy storage system. The system controls the order in which battery packs are disconnected from the common traction voltage bus by opening closed contactors based on their measured current and health level, ensuring that contactors with lower health levels or currents are opened first.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If contactors are frequently switched to meet power demands, then the system can adapt to varying power requirements, but contactor wear increases leading to premature failure
Solution Approach 1:
The system changes the operational parameters of contactors by monitoring their health levels and measured currents, dynamically adjusting which contactors are opened or closed based on real-time conditions rather than fixed switching patterns, thereby reducing wear while maintaining power adaptability
Solution Approach 2:
The control unit continuously monitors the health level and current of each contactor, using this feedback information to make intelligent decisions about contactor operation, avoiding unnecessary switching of already-worn contactors and preventing premature failure
2Ease of operation
If contactors are opened frequently to disconnect battery packs, then the system can manage battery pack operations, but mechanical and electrical wear increases
Solution Approach 1:
The system monitors and compares parameters (health level and measured current) of multiple contactors, changing the operational status of contactors based on which ones have the lowest measured current or health level, thereby distributing wear more evenly and extending overall system lifespan
Solution Approach 2:
The control unit proactively identifies contactors with low health levels or low measured currents before they fail, and prioritizes opening these contactors first, preventing sudden failures and allowing for planned maintenance
Data Source
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AI summary
A computer system comprising processing circuitry configured to: - determine measured current over each one of a plurality of contactors of a switching arrangement of an energy storage system of a vehicle, - determine a health level of each contactor, - control the order in which the battery packs are disconnected from the common traction voltage bus, until all of the battery packs are disconnected, by opening closed contactors according to the following: - open the closed contactor having the lowest measured current in response to that no closed contactor has a health level deviating from a mean health level of all contactors with more than a first predetermined value, and - open the closed contactor having the lowest health level in response to that the health level of such closed contactor deviates from the mean health level of all contactors with a value of more than the first predetermined value.