Battery State Estimation via External Short Electromagnetic Field Analysis
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Solution Overview
Problem
Current methods for detecting the state of health and state of charge of energy devices, such as batteries, are costly and require complex instruments, limiting their application to single cells and research purposes. Additionally, these methods fail to detect abnormalities, such as electrical shorts, in a timely manner, which can lead to safety issues and device failure.
Innovation Solution
The system utilizes a short generator to create an external short across a known resistance, and a sensor to measure the change in electromagnetic field produced by the energy device. This data is analyzed to estimate the internal resistance of the energy device, which is then used to determine the state of health and state of charge without the need for costly hardware or cycling the battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If EIS method is used to measure cell resistance for state of charge and state of health estimation, then measurement precision is improved, but device complexity and cost increase due to requirement of AC signal generation equipment and wide frequency range measurements
Solution Approach 1:
The patent extracts only the essential measurement capability needed for state estimation by using simple voltage and current measurements during normal operation, eliminating the need for complex AC signal generation equipment while maintaining measurement precision through mathematical processing of the extracted operational data
Solution Approach 2:
The patent replaces the mechanical/electrical measurement system (AC signal generation and impedance measurement equipment) with a computational approach that uses standard voltage and current sensors combined with mathematical models to estimate state of charge and state of health, thereby reducing device complexity
2Measurement precision
If OCV delay method is used to estimate internal states, then measurement precision is improved, but loss of time increases due to requirement of precise voltage measurement during cycling and stabilization delays
Solution Approach 1:
The patent performs preliminary characterization of the cell during normal operation by continuously monitoring voltage and current, building up data that can be used for state estimation without requiring additional stabilization time or cycling, as the measurements are taken during regular charge-discharge operations
Solution Approach 2:
The patent uses periodic voltage and current measurements during normal cycling operations to continuously update state estimates, eliminating the need for separate OCV stabilization periods while maintaining measurement precision through regular data collection during operational cycles
3Reliability
If sensors are used to detect thermal runaways, then reliability is improved, but loss of time increases as sensors only detect secondary outcomes after damage has progressed extensively
Solution Approach 1:
The patent performs preliminary detection of internal resistance changes and abnormal heating trends during normal operation, identifying potential thermal runaway conditions before they progress to catastrophic failure, thereby providing early warning while maintaining reliability through continuous monitoring of electrical parameters that precede thermal events
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 allows for rapid estimation of state of charge and state of health, enabling faster charging and longer battery life, while also detecting electrical shorts early, thereby preventing thermal runaways and extending the lifespan of energy devices.
Implementation Method 1
a sensor to measure the change in electromagnetic field produced by the energy device
Data Source
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AI summary
A system and method for monitoring characteristics of an electric energy device includes generating an external short from the electric energy device. The external short occurs at a known distance from a sensor and has at least one known external resistance. The received signal representing change in electromagnetic field due to the applied external short may be analyzed to determine a signal parameter that is then analyzed in comparison to a lookup table, based on the known conditions inclduig distance, temperature and the external resistance. The output of this analyses in comparison with expected values may be utilized to identify a characteristic of the energy device.