Battery Thermal Network Modeling for Internal Temperature Estimation
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Solution Overview
Problem
Existing battery thermal management systems struggle to accurately estimate internal temperature in real-time due to non-uniform temperature distribution within batteries, leading to performance and safety issues, and existing methods are either highly demanding or inaccurate under complex conditions.
Innovation Solution
A method involving off-line testing to establish a thermal equivalent circuit model using multi-objective function fitting, determining optimal parameters, and applying it to real-time vehicle operations to estimate internal battery temperature accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a battery heat transfer model equates the battery surface to one temperature point, then the model complexity is reduced, but the temperature measurement accuracy deteriorates due to non-uniform temperature distribution on the battery surface
Solution Approach 1:
The battery surface is segmented into multiple temperature measurement points rather than using a single point. Each point captures local temperature characteristics, and the model processes these distributed measurements to estimate internal temperature, thereby resolving the contradiction between model simplicity and measurement accuracy by distributing sensors strategically across the surface.
Solution Approach 2:
The model transitions from treating the battery surface as a zero-dimensional single point to a multi-dimensional distributed measurement system. By incorporating spatial distribution of temperature points across the battery surface, the model captures thermal gradients and non-uniform temperature fields, improving accuracy without proportionally increasing complexity through sophisticated physics-based models.
2Measurement precision
If electrochemical impedance spectroscopy is used to estimate internal battery temperature, then temperature estimation accuracy is improved, but the test system complexity and requirements increase significantly
Solution Approach 1:
The invention extracts the essential thermal estimation function from complex electrochemical impedance spectroscopy by using a simplified thermal equivalent circuit model. This extracted model retains the core capability of estimating internal temperature while removing the need for complex impedance measurement systems, achieving accuracy with significantly reduced test system requirements.
Solution Approach 2:
The patent replaces expensive, complex electrochemical impedance measurement equipment with simpler, more accessible temperature sensors and computational models. The simplified approach uses readily available surface temperature measurements combined with thermal modeling, eliminating the need for specialized test equipment while maintaining practical temperature estimation accuracy for vehicle applications.
3Ease of operation
If functional relationship methods are used to estimate internal temperature from surface temperature, then the implementation simplicity is improved, but the accuracy deteriorates under complex operating conditions
Solution Approach 1:
The model dynamically adjusts thermal parameters such as thermal resistance and thermal capacity based on operating conditions (charge/discharge rate, ambient temperature, battery state of charge). This allows the simplified thermal equivalent circuit model to adapt to complex operating conditions, maintaining accuracy while preserving implementation simplicity through a computationally efficient framework.
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
Accurately estimates battery internal temperature in real-time, optimizing operating conditions and enhancing safety by reducing reliance on surface temperature measurements.
Implementation Method 1
a battery heat transfer model in the related art equates a battery surface to one temperature point
Implementation Method 2
heat generation and heat dissipation are not uniform inside the battery, and thus there is a temperature field distribution inside the battery
Data Source
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AI summary
A battery internal temperature information processing method, a computer device, and a storage medium that first acquire off-line testing data for off-line testing a battery module and construct an equivalent thermal network model from the off-line testing data, determine optimal model parameters of the equivalent thermal network model based on a multi-objective function fitting method; Thereafter, a first battery internal temperature estimate of the battery of the vehicle at a first moment in actual operation of the vehicle is determined, in turn, based on the acquired initial state vector values of the battery of the vehicle, first operational data at a first moment in actual operation of the vehicle, and an equivalent thermal network model including the optimal model parameters.