Battery Thermal Modeling for Indirect Current Limit Estimation
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Solution Overview
Problem
Existing battery systems face challenges in accurately estimating current and power capabilities due to limited computational resources and non-generalizable thermal models, leading to overheating and degradation of components like electrode tabs and power electronics, which are difficult to monitor directly.
Innovation Solution
A predictive thermal model using a first-order ordinary differential equation correlates a measured temperature with an unmonitored component's temperature, determining maximum current and power limits to adjust operating conditions and prevent overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex thermal diffusion models are implemented to accurately estimate internal temperatures, then temperature estimation accuracy is improved, but computational resource requirements and model complexity increase
Solution Approach 1:
The patent transforms the complex thermal diffusion model into a simplified linear regression model by changing the mathematical parameters and relationships. Instead of solving partial differential equations with multiple empirical parameters, the invention uses a linear relationship between monitored temperature and estimated internal temperature, requiring only basic arithmetic operations that are computationally efficient while maintaining sufficient accuracy for battery management applications
Solution Approach 2:
The patent extracts only the essential temperature estimation functionality from the complex thermal diffusion model. By focusing solely on the relationship between external temperature sensors and internal component temperatures, the invention removes unnecessary computational complexity while retaining the core capability to estimate temperatures of unmonitored components
2Measurement precision
If temperature sensors are placed on all critical components including electrode tabs and power electronics, then temperature monitoring accuracy is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent uses the monitored temperature of accessible components (such as battery cell bodies or PCB surfaces) as an intermediary to indirectly estimate the temperatures of unmonitored critical components. This intermediary approach allows the system to infer internal temperatures through thermal coupling relationships without requiring direct sensor contact with difficult-to-access components like electrode tabs or power electronics devices
Solution Approach 2:
The patent creates a universal temperature estimation algorithm that can be applied to any component in the battery system, whether monitored or unmonitored. The same linear regression model and thermal coupling principles used for estimated temperature calculation can determine current and power capabilities of any component, making the system universally applicable across different battery configurations and component types
3Measurement precision
If extensive empirical parameters are used to accurately model internal temperatures, then temperature modeling accuracy is improved, but data acquisition difficulty and calibration time increase
Solution Approach 1:
The patent reduces the number and complexity of empirical parameters from multiple thermal conductivity and thermal capacitance values to a single calibration factor or offset value. This parameter simplification transforms the complex thermal model into a practical implementation that requires minimal empirical data while maintaining sufficient accuracy for real-world battery management applications
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 model effectively mitigates overheating in unmonitored battery components by accurately estimating current and power capabilities, protecting components from degradation through real-time adjustments.
Implementation Method 1
such algorithms may assume thermal conduction is the sole mechanism of heat transfer (as may be the case between an external cell body and a cell interior, for example)
Implementation Method 2
For some thermally connected pairs of battery components, other factors may influence heat transfer therebetween
Data Source
AI summary
Methods and systems are provided for predictive thermal models for determining current and power capabilities of battery components of a battery-powered system. In one example, a method may include measuring a reference temperature of a first component of the battery-powered system, correlating a target temperature of a second component of the battery-powered system to the reference temperature, determining a maximum current manageable by the second component over a predetermined duration based on the target temperature, and responsive to an actual current at the second component being requested greater than the maximum current during the predetermined duration, adjusting one or more operating conditions of the battery-powered system to maintain the actual current below the maximum current. In some examples, the first component may be different from the second component. In this way, the methods and systems provided herein may mitigate overheating in a battery-powered system by altering an operating state thereof.