Battery SOC Estimation Using Temperature and Overvoltage Profiles
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Solution Overview
Problem
Existing battery management systems face challenges in accurately estimating the state of charge (SOC) and unusable capacity due to variations in current intensity, temperature, and aging, which affects the prediction of available capacity and remaining usage time.
Innovation Solution
An electronic device equipped with temperature, current, and voltage sensors, along with a processor that uses a battery model to estimate a temperature profile, determine an overvoltage profile, revise it based on SOC and voltage, and calculate an unusable SOC, thereby estimating the available capacity and remaining usage time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If battery state is estimated using integration of currents or battery models, then SOC estimation can be performed, but accuracy deteriorates due to variations in current intensity, temperature, and aging
Solution Approach 1:
The patent introduces temperature profile and overvoltage profile as intermediary variables to bridge the gap between measurable quantities (temperature, current, voltage) and the target variable (SOC). By estimating temperature profile from measured temperature and current, and then deriving overvoltage profile from temperature profile, the system creates a chain of inference that improves SOC estimation accuracy while accounting for environmental variations and aging effects
Solution Approach 2:
The patent dynamically adjusts estimation parameters based on operating conditions. The overvoltage profile is revised using current SOC and voltage measurements, and the estimation process adapts to different current intensities and temperature conditions. This parameter adaptation allows the system to maintain accuracy across varying operational states and aging stages
2Measurement precision
If complex battery models are used to improve estimation accuracy, then measurement precision improves, but computational cost increases
Solution Approach 1:
The patent segments the complex battery state estimation problem into distinct modules: temperature profile estimation from temperature and current measurements, overvoltage profile determination from temperature profile, and SOC calculation from overvoltage profile and voltage measurements. This modular segmentation reduces computational complexity while maintaining estimation accuracy by processing information in manageable stages rather than solving a single complex system
Data Source
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AI summary
An electronic device for estimating a battery state and an operating method thereof are disclosed. The electronic device including a temperature sensor configured to measure a temperature of the battery, a current sensor configured to measure a current of the battery, a voltage sensor configured to measure a voltage of the battery, and a processor configured to estimate a temperature profile of the battery based on the temperature and the current of the battery and a battery model, determine an overvoltage profile of the battery based on the temperature profile, revise the overvoltage profile based on a current state of charge (SOC) and the voltage of the battery, and estimate an unusable SOC of the battery based on the revised overvoltage profile and an open circuit voltage (OCV) profile of the battery.