Battery Voltage Estimation Using Linearized Open-Circuit Potential
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Solution Overview
Problem
Current battery management systems face challenges in accurately estimating battery voltage due to the complexity and computational intensity of existing electrochemical models, which hinders real-time state of charge, state of health, and power management in electric vehicles.
Innovation Solution
A computer-implemented method that linearizes the open circuit potential of an electrochemical battery model using piece-wise linearization with a specified number of knots to minimize squared-approximation error, allowing for faster and more accurate voltage estimation, thereby simplifying the battery model for real-time applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rigorous physics-based P2D model is used to model battery electrochemical processes, then accuracy and precision of battery voltage estimation is improved, but computational time and model complexity increase significantly
Solution Approach 1:
The patent applies segmentation by dividing the continuous open circuit potential function into multiple linear segments (piece-wise linearization) defined by knots. This segmentation transforms the complex non-linear P2D model into a simplified model that maintains accuracy while reducing computational time, enabling real-time battery voltage estimation without the full computational burden of the original physics-based model.
Solution Approach 2:
The patent changes the parameter representation of the open circuit potential from a continuous non-linear function to a set of discrete linear segments with specific knot points. This parameter transformation allows the model to retain essential electrochemical behavior while dramatically reducing computational complexity and execution time for real-time applications.
2Measurement precision
If a rigorous physics-based P2D model is used to model battery electrochemical processes, then accuracy and precision of battery voltage estimation is improved, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the continuous open circuit potential function into multiple linear segments (piece-wise linearization) defined by knots. This segmentation transforms the complex non-linear P2D model into a simplified model that maintains accuracy while reducing computational time, enabling real-time battery voltage estimation without the full computational burden of the original physics-based model.
Solution Approach 2:
The patent changes the parameter representation of the open circuit potential from a continuous non-linear function to a set of discrete linear segments with specific knot points. This parameter transformation allows the model to retain essential electrochemical behavior while dramatically reducing computational complexity and execution time for real-time applications.
3Measurement precision
If piece-wise linearization with more knots is used to minimize squared-approximation error, then voltage estimation accuracy is improved, but computational effort increases
Solution Approach 1:
The patent applies partial action by using a moderate number of knots (not the maximum possible) that provides sufficient accuracy for practical applications. This partial linearization achieves the necessary voltage estimation accuracy while avoiding the excessive computational effort that would result from using too many knots, thus maintaining real-time estimation capability.
Solution Approach 2:
The patent changes the parameter representation of the open circuit potential from a continuous non-linear function to a set of discrete linear segments with specific knot points. This parameter transformation allows the model to retain essential electrochemical behavior while dramatically reducing computational complexity and execution time for real-time applications.
Data Source
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AI summary
In a method for estimating a voltage of a battery a given electrochemical battery model is provided, wherein one parameter of the electrochemical battery model is an open circuit potential. The open circuit potential is linearized. The voltage of the battery is estimated by means of the electrochemical battery model with the linearized open circuit potential.