Battery Pack Temperature Sensing for Accurate Overheat Detection
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Solution Overview
Problem
Existing battery management systems face challenges in accurately detecting overheating due to limitations in the number of sensing channels and high costs of analog front-end integrated circuits, leading to potential erroneous detection of overheating in lithium-ion batteries.
Innovation Solution
A battery pack with first and second measurement circuits using temperature measurement elements with different resistance characteristics, such as PTC and NTC devices, to accurately determine overheating by combining their outputs and using resistance calculation formulas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single type of temperature measurement element (e.g., NTC only) is used, then the device complexity is reduced, but measurement precision deteriorates due to inability to distinguish actual overheating from erroneous detection
Solution Approach 1:
The patent combines two different types of temperature measurement elements (NTC and PTC) into a single measurement system. The NTC element provides primary temperature measurement while the PTC element serves as a reference for detecting measurement errors. By merging these complementary measurement approaches, the system achieves higher measurement precision without proportionally increasing complexity, as both elements are integrated into the same control circuit architecture.
Solution Approach 2:
The system uses the PTC element as a feedback reference to detect when the NTC element's measurement becomes unreliable. When the PTC-measured temperature deviates from the NTC-measured temperature beyond a threshold, the system identifies this as a measurement error condition and adjusts its overheating determination logic accordingly. This feedback mechanism enables the system to maintain high measurement precision by compensating for erroneous detections.
2Measurement precision
If multiple temperature measurement elements are used to improve detection accuracy, then measurement precision improves, but device complexity increases due to additional sensing channels and circuit requirements
Solution Approach 1:
The control circuit is designed with multi-functionality to handle both NTC and PTC measurement elements simultaneously. The same control circuit that processes NTC temperature data also processes PTC temperature data and uses it for error detection. This universal circuit design avoids the need for separate dedicated circuits for each sensor type, thereby improving measurement precision while minimizing the increase in device complexity.
Solution Approach 2:
The PTC temperature measurement element acts as an intermediary reference for validating the NTC measurements. Rather than requiring complex independent verification systems, the PTC element serves as a simple mediator that provides a reference measurement to identify when NTC readings are erroneous. This intermediary approach enables accurate overheating detection without proportionally increasing circuit complexity.
3Measurement precision
If advanced temperature measurement systems are implemented, then measurement precision improves, but manufacturing cost increases due to additional sensing channels and integrated circuits
Solution Approach 1:
The system uses a simplified copying approach where the PTC element replicates the temperature sensing function in a different technological form. Rather than using complex redundant NTC circuits, the patent copies the temperature measurement capability using a PTC element with opposite temperature coefficients. This allows the system to achieve measurement precision improvement while keeping manufacturing costs relatively low, as PTC elements are simple passive components similar to NTC elements.
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 solution enables precise detection of overheating in battery cells, reducing erroneous detections and enhancing safety by utilizing a battery management system that integrates multiple temperature measurement elements with distinct resistance profiles.
Implementation Method 1
first and second temperature measuring elements having different resistance characteristics according to temperature change
Implementation Method 2
first and second temperature measuring elements having different resistance characteristics according to temperature change
Data Source
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AI summary
A battery pack includes battery cells (C), a first measurement circuit unit (M1) and a second measurement circuit unit (M2) each configured to measure temperature information of the battery cells (C) and respectively including a first-type temperature measurement element (P) and a secondtype temperature measurement element (N) different from each other and having different characteristics of a resistance change according to a temperature change, the first measurement circuit unit (M1) and the second measurement circuit unit (M2) being formed on a common base substrate (S) or on different individual base substrates (S3, S4), and a battery management system (BMS) configured to determine whether the battery cells (C) are overheated based on the temperature information of the battery cells (C).