Battery Equalization Circuit Fault Detection Using ON/OFF Voltage Estimation
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Solution Overview
Problem
Existing battery abnormality detection devices cannot identify abnormalities such as half shorting and leakage of elements, which are critical for ensuring the reliability and safety of battery systems.
Innovation Solution
A battery abnormality detection device that includes a processor configured to acquire voltages from a battery cell when a switch in the equalization circuit is ON and OFF, estimate the voltage when the switch is OFF based on the voltage when it is ON, and determine if an abnormality has occurred by comparing the estimated and measured voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage detection is performed only when the discharge circuit is operating or stopped, then protection circuit disconnection can be identified, but abnormalities such as half shorting and leakage of elements cannot be detected
Solution Approach 1:
The patent applies preliminary action by performing voltage detection at multiple predetermined timings (when switch is ON, OFF, and at intermediate timing) before actual abnormalities occur. This allows the system to establish baseline voltage characteristics and detect deviations that indicate element failures or leakage, enabling proactive abnormality detection rather than waiting for circuit failure states.
Solution Approach 2:
The patent implements feedback by comparing voltage detection results across different switch states and timings. The detection unit analyzes voltage changes and provides feedback to determine whether abnormalities such as half shorting or leakage have occurred. This feedback mechanism enables continuous monitoring and identification of element degradation that would not be apparent from single-state measurements.
2Ease of operation
If simple voltage difference checking is used to identify protection circuit disconnection, then the detection method is simple, but it cannot identify half shorting and leakage abnormalities
Solution Approach 1:
The patent applies partial action by performing voltage detection at selectively predetermined timings rather than continuously. It detects voltage when the switch is ON, when it is OFF, and at intermediate timing between these states. This partial sampling approach maintains operational simplicity while providing sufficient data points to identify various abnormalities including half shorting and leakage that would not be detected by simple two-state comparison.
3Reliability
If voltage detection is performed at multiple timings and conditions, then element failures and leakage can be detected, but the detection process becomes more complex
Solution Approach 1:
The patent applies universality by designing a detection system that performs multiple functions through a single integrated approach. The voltage detection unit detects various types of abnormalities (protection circuit disconnection, half shorting, element leakage) using a unified multi-timing detection methodology. This universal detection framework handles diverse failure modes without requiring separate detection circuits or complex specialized procedures for each abnormality type.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device effectively detects abnormalities including failures and leakages of elements in the battery system, ensuring reliable operation and safety by implementing a failsafe mechanism to stop power supply in case of an abnormality.
Implementation Method 1
including a detector connected to the battery cell in parallel to the discharge circuit so as to detect a voltage of the battery cell
Data Source
AI summary
A battery abnormality detection device that: for an equalization circuit including a discharge circuit provided with a switch that, in a case of being switched ON, causes a battery cell to discharge, and including a detector connected to the battery cell in parallel to the discharge circuit so as to detect a voltage of the battery cell, acquires a first voltage in a case in which the switch has been switched OFF and a second voltage in a case in which the switch has been switched ON, as detected by the detector, and estimates, from a detected value of one of the acquired first voltage or second voltage, an estimated value of another of the acquired first voltage or second voltage, and determines whether or not an abnormality has occurred in the equalization circuit based on the detected value and the estimated value.