Parallel Battery Cell Disconnection Detection via Discharge Voltage
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Solution Overview
Problem
In parallel connected battery systems, disconnection due to open parallel connection lines or CID operations leads to overcurrent flow, causing cell deterioration and performance degradation, necessitating a method to detect such failures in real-time.
Innovation Solution
A method and system that acquire and analyze discharge voltage data using machine learning techniques to identify changes indicative of CID operations or open parallel connection lines, generating a cell connection failure detection signal to prevent battery deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If parallel connection lines are used to connect battery cells, then battery capacity and power are increased, but connection faults cause overcurrent and cell deterioration
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring discharge voltage values and comparing them against reference data to detect connection faults. The BMS receives voltage signals from detection circuits, processes the data through comparison and analysis, and generates fault detection signals when abnormalities are identified, enabling real-time feedback on connection status.
Solution Approach 2:
The patent introduces intermediary detection circuits and control units between the parallel-connected battery cells and the external load. These intermediaries monitor voltage changes and facilitate early detection of connection faults before they cause overcurrent damage, acting as mediators that prevent direct harmful effects.
2Reliability
If CID protection elements are installed in battery cells, then safety is improved, but CID operation causes disconnection and overcurrent in remaining cells
Solution Approach 1:
The patent performs preliminary detection of CID operations by monitoring discharge voltage changes before overcurrent can damage the battery. The system identifies CID activation through voltage pattern recognition and immediately generates fault detection signals, enabling preventive action before harmful overcurrent effects occur in remaining cells.
Solution Approach 2:
The patent converts the voltage change caused by CID operation (which would normally indicate a fault) into a detectable signal for early fault identification. By monitoring discharge voltage patterns, the system transforms the CID's protective disconnection action into a measurable indicator that triggers fault detection and prevents further damage.
3Difficulty of detecting and measuring
If discharge voltage monitoring is performed to detect connection faults, then fault detection capability is improved, but measurement precision requirements increase
Solution Approach 1:
The patent changes the monitoring parameter from absolute voltage values to voltage change patterns and differences. By comparing voltage changes across multiple cells and against reference data, the system reduces the impact of measurement precision limitations and focuses on detecting relative changes that indicate connection faults.
Solution Approach 2:
The patent monitors voltage changes at specific critical points and intervals rather than continuously tracking all parameters with maximum precision. The detection circuit focuses on measuring voltage differences and changes that are sufficient to identify connection faults, rather than requiring complete precise measurement of all battery parameters.
Data Source
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AI summary
The present invention relates to a method and system for detecting connection failure of a parallel connection cell, and for a battery that is being discharged by the operation of an external device (e.g. vehicle), by detecting whether there is a section matching the amount of change in the discharge voltage value when a cell connection failure condition occurs due to a pre-prepared CID operation or an open parallel connection line from the change in the discharge voltage value of the battery being discharged, a cell connection failure due to a CID operation of a corresponding battery or an open parallel connection line may be detected.