Battery Module Voltage Difference Fault Detection
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Solution Overview
Problem
Existing battery fault detection methods are inefficient due to high costs and lack of precision, often requiring temperature measurements and applying safety margins, which can lead to late detection of contact resistance faults and increased risk of battery fires.
Innovation Solution
A method that compares the voltage differences between sets of battery modules connected in series, using a correction coefficient to determine a value x, which is compared to a threshold to detect faults without requiring temperature measurements, allowing for precise detection of contact resistance issues and reducing false alarms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature measurement and electrothermal models are used to detect contact resistance, then detection capability is provided, but measurement precision deteriorates and false detections increase due to safety margins
Solution Approach 1:
The patent replaces temperature-based thermal models with a direct electrical voltage measurement approach. By measuring the voltage drop across battery modules and comparing it to expected values based on current and internal resistance, the system directly detects contact resistance faults without relying on temperature sensors or complex thermal models, thereby eliminating false detections from safety margins.
Solution Approach 2:
The patent introduces voltage measurement as an intermediary parameter to detect contact resistance faults. Instead of directly measuring temperature or contact resistance, the system uses voltage drops across modules as a mediator that reflects contact resistance conditions, providing a more precise and direct detection method.
2Measurement precision
If safety margins are applied to contact resistance values, then false detections are reduced, but detection timing is delayed and fire risk increases
Solution Approach 1:
The patent substitutes temperature-based detection with direct voltage measurement that can detect contact resistance changes in real-time without requiring safety margins. The system compares actual voltage drops to calculated expected values based on current and known internal resistance, enabling immediate detection of faults as they occur.
Solution Approach 2:
The patent performs preliminary calculations of expected voltage drops based on current and internal resistance before actual fault detection. This allows the system to identify deviations from normal operation immediately, enabling early detection of contact resistance faults before they lead to fire hazards.
3Reliability
If complex electrothermal models are used for contact resistance analysis, then comprehensive analysis is achieved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex electrothermal models with a straightforward electrical circuit analysis approach. By using Ohm's law and voltage measurement, the system achieves comprehensive fault detection without requiring temperature sensors, thermal models, or complex computational algorithms, significantly simplifying the detection system.
Solution Approach 2:
The patent extracts the essential detection function from complex electrothermal models by focusing solely on voltage measurement and comparison. This extraction eliminates unnecessary temperature sensing, thermal modeling, and complex calculations, retaining only the core voltage-based detection mechanism.
4Measurement precision
If voltage comparison method is used without temperature measurement, then measurement precision improves and false alarms reduce, but detection coverage may be limited
Solution Approach 1:
The patent makes the voltage comparison method universal by demonstrating that voltage drops reflect multiple factors including contact resistance, internal resistance variations, and current changes. This single voltage-based approach can detect various fault types and operational conditions, providing broad detection coverage without requiring separate temperature or other sensors.
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
This method enhances the precision of fault detection, reduces the risk of false alarms, and enables early detection of smaller damages, thereby preventing harmful effects and lowering repair costs.
Implementation Method 1
a first means for measuring a first voltage Vi of the first set of modules Ei, a second means for measuring a second voltage Vj of the second set of modules Ej, each module comprising at least one cell and a means for measuring the voltage VCz, VMc of the cell
Data Source
Figure 1
AI summary
Method for detecting a fault in a battery comprising a first and a second set of modules (Ei, Ej) connected in series and a first and a second means for measuring a first and second voltage (Vi, Vj), respectively, of each set (Ei, Ej), each module (1) comprising at least one cell (2) and a means for measuring the voltage (VCz, VMc) of the cell (2), said method comprising the following successive steps: - determining a value x according to the formula I: (I) wherein: * Vi and Vj are the first and second voltage, respectively, of the first and second set of modules (Ei, Ej), * ΔVi et ΔVj are the voltage Vi and the voltage Vj subtracted from the sum of each voltage (VCz, VMc) of the cells (2) of the first set (Ei) and the second set (Ej), respectively, * k is a correction coefficient, - comparing said value x with a threshold, and - confirming that one of the sets of modules (Ei, Ej) has a fault when said value x exceeds said threshold.