Vehicle Battery State of Energy Estimation Using Mode-Dependent Parameters
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Solution Overview
Problem
Current methods for determining the state of energy (SOE) of rechargeable batteries in vehicles are not accurate enough to provide reliable information on the remaining charge and discharge energy, which is crucial for determining the travel range and charging time.
Innovation Solution
A method that calculates the state of energy (SOE) by considering parameters related to the operation mode of the vehicle, such as current, resistance, and allowed state of charge (SOC) levels, which vary depending on the vehicle mode, allowing for a more precise estimation of remaining charge and discharge energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional SOC-based battery capacity estimation methods are used, then the measurement process is simple, but the measurement precision of remaining energy is insufficient
Solution Approach 1:
The patent changes the parameters used for battery state estimation from only SOC (state of charge) to include multiple parameters: SOC, SOH (state of health), temperature, and operating mode. This multi-parameter approach significantly improves the precision of remaining energy estimation while accounting for the complex relationships between battery chemistry, thermal conditions, and operational context.
Solution Approach 2:
The patent implements dynamic adjustment of the energy calculation model based on operating mode (charging, discharging, idle) and battery state (temperature, SOC level). The system dynamically selects appropriate efficiency factors and calculation methods depending on the current operating conditions, making the model adaptive rather than static. This resolves the contradiction by making the complexity conditional rather than constant.
2Reliability
If fixed efficiency factors are used in energy calculations, then the calculation process is simple, but the reliability of energy estimation deteriorates under varying operating conditions
Solution Approach 1:
The patent replaces fixed efficiency factors with dynamic efficiency factors that automatically adjust based on operating mode (charging, discharging, idle), temperature ranges, and SOC levels. The system maintains a library of mode-specific efficiency factors and selects the appropriate ones based on current conditions, significantly improving reliability while keeping the complexity manageable through systematic organization.
Solution Approach 2:
The system incorporates feedback mechanisms where the actual battery behavior is monitored and compared against model predictions. The efficiency factors are refined based on observed deviations, creating a self-correcting system that improves reliability over time. This feedback loop allows the system to adapt to aging batteries and changing operating patterns.
3Measurement precision
If mode-dependent parameters are incorporated into SOE calculation, then the precision of travel range information is improved, but the difficulty of detecting and measuring increases
Solution Approach 1:
The patent integrates multiple monitoring functions into a unified battery management system that simultaneously tracks SOC, SOH, temperature, and operating mode. The system uses a single multi-functional controller that handles all parameter detection and the SOE calculation, reducing the overall system complexity despite the increased number of parameters being monitored. This universal approach improves precision without proportionally increasing measurement difficulty.
Data Source
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AI summary
The invention relates to a method for determining a value of the state of energy (SOE) of a rechargeable battery (5) in a vehicle (1; 1), said battery (5) being connected to an electric consumer (4); said method comprising: determining the state of charge (SOC) as a measure of the present capacity of said battery (5); and determining said state of energy (SOE) as an indication of at least the remaining charge and discharge energy of said battery (5). The method according to the invention further comprises: calculating and determining said value of the state of energy (SOE) based on at least one parameter (I, R, SOCmax, SOCmin) which is related to the operation of said electric consumer (4) and where said at least one parameter (I, R, SOCmax, SOCmin) varies depending on a mode for operating said vehicle (1; 1) or electric consumer (4) during charging or discharging of said battery (5). The invention also relates to an arrangement for determining a value of the state of energy (SOE) of a rechargeable battery (5) in a vehicle (1; 1).