Switch Deterioration Detection Using Voltage Comparison
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Solution Overview
Problem
Existing methods for detecting switch deterioration in battery packs are unreliable and imprecise due to temperature measurements influenced by ambient conditions, rather than the switch's actual temperature, leading to inaccurate detection of switch performance degradation.
Innovation Solution
A switch deterioration detection device and method that serially connects a resistor with the battery and uses differential amplifiers to compare voltage differences between the switch and the resistor, with a comparator determining switch deterioration based on output voltage levels, and calculates the turn-on resistance value using the resistor's resistance and amplification ratios when output voltages are equal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature sensor is used to monitor switch temperature, then switch deterioration can be detected, but the detection precision deteriorates because the measured temperature is influenced by ambient environment rather than switch actual temperature
Solution Approach 1:
The patent introduces a resistor as an intermediary element connected in series with the switch. By measuring the voltage across this resistor and comparing it with the voltage across the switch, the system indirectly detects switch resistance changes without directly measuring switch temperature, thereby avoiding ambient temperature interference
Solution Approach 2:
The patent replaces the direct thermal measurement approach (mechanical/thermal system) with an electrical measurement approach. Instead of measuring temperature directly with a temperature sensor, the system measures electrical resistance changes through voltage comparisons, which are then correlated to switch deterioration
2Measurement precision
If voltage difference amplification and comparison is used to detect switch deterioration, then measurement precision is improved, but device complexity increases due to additional differential amplifiers and comparator circuitry
Solution Approach 1:
The patent divides the detection function into separate modular components: differential amplifiers for voltage amplification, comparator for voltage comparison, and control unit for decision-making. This segmentation allows each component to perform a specific function efficiently while maintaining overall system precision
Solution Approach 2:
The patent uses differential amplifiers to create balanced signal paths that amplify voltage differences while rejecting common-mode signals. By maintaining equipotential references and using symmetric circuit configurations, the system achieves high precision measurement without requiring excessively complex shielding or isolation circuits
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 approach provides precise and reliable detection of switch deterioration, independent of ambient temperature, and accurately calculates the turn-on resistance value, preventing damage and fires in battery systems by ensuring exact detection of switch performance.
Implementation Method 1
amplifying a voltage difference between both ends of the switch to output the amplified voltage difference as a first output voltage
Implementation Method 2
amplifying a voltage difference between both ends of the resistor to output the amplified voltage difference as a second output voltage
Implementation Method 3
compare levels between the first and second output voltages
Implementation Method 4
a switch controlling charge and discharge of the battery
Implementation Method 5
a resistor serially connected with a battery
Data Source
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AI summary
Provided are switch deterioration detection device and method. More particularly, the switch deterioration detection device includes: a resistor serially connected with a battery in which charge and discharge are controlled through a switch; a first differential amplifier configured to amplify a voltage difference between both ends of the switch to output the amplified voltage difference as a first output voltage; a second differential amplifier configured to amplify a voltage difference between both ends of the resistor to output the amplified voltage difference as a second output voltage; a comparator configured to compare levels between the second and second output voltages; and a controller configured to determine whether the switch deteriorates based on the compared result of the comparator.