Hybrid Vehicle Battery SOC Control via Temperature Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-voltage batteries in hybrid electric vehicles face diminished performance and battery life due to temperature-related issues, particularly in cold conditions, where overcharging or undercharging can lead to inadequate power for vehicle starting and reduced fuel economy.
Innovation Solution
A method and system that predict battery temperature to determine a temperature-dependent state-of-charge (SOC) range, adjusting the SOC limits to maintain optimal charge levels, ensuring sufficient power and optimizing battery life and fuel economy by controlling charge flow through a battery control module and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the battery temperature is low (cold conditions), then the available amperage and power are reduced, but maintaining a high SOC range to compensate increases the risk of overcharging and diminishes battery life
Solution Approach 1:
The patent applies dynamics by making the SOC range adjustable and temperature-dependent rather than fixed. The battery control module dynamically modifies the desired SOC range based on predicted battery temperature, allowing the system to adapt to varying thermal conditions and optimize both power availability and battery longevity accordingly
Solution Approach 2:
The patent uses preliminary action by predicting future battery temperature before it actually occurs. The battery control module predicts the battery temperature based on current conditions and uses this prediction to proactively adjust the SOC range in advance, preventing potential overcharging or undercharging issues before they arise
2Power
If the SOC range is expanded to ensure sufficient power in cold conditions, then vehicle starting capability is improved, but fuel economy deteriorates due to increased charge/discharge cycles
Solution Approach 1:
The patent applies parameter changes by adjusting the SOC range parameters based on temperature predictions. The battery control module modifies the upper and lower SOC limits as a function of predicted battery temperature, ensuring optimal power availability while minimizing unnecessary charge/discharge cycles that would waste fuel
3Reliability
If the battery temperature prediction is used to adjust SOC range, then battery performance is optimized, but system complexity increases due to additional control logic
Solution Approach 1:
The patent applies universality by integrating the temperature prediction and SOC range adjustment functionality within the existing battery control module. Rather than adding a separate complex system, the battery control module performs multiple functions including temperature monitoring, prediction, SOC range determination, and charge/discharge control, thereby optimizing battery performance without proportionally increasing system complexity
Data Source
AI summary
A system and method for controlling a state-of-charge (SOC) of a vehicle battery, such as a high-voltage battery used by a hybrid electric vehicle (HEV) for vehicle propulsion, so that the SOC is maintained within a desired SOC range that is temperature-dependent. In an exemplary embodiment, the system and method use a battery temperature prediction to determine a desired SOC range, and then control the amount of charge on the vehicle battery such that the SOC is maintained within the desired SOC range. As the battery temperature prediction goes lower (i.e., as it gets colder), the desired SOC range may need to be adjusted or shifted upwards in order to account for increased internal battery resistance and to ensure that the vehicle battery has enough power to start the vehicle. Similarly, as the battery temperature prediction goes higher (i.e., as it gets warmer), the desired SOC range may need to be adjusted or shifted downwards in order to reduce degradation effects and improve battery. The exemplary system and method control the SOC of the vehicle battery and may seek to optimize a number of different parameters, including battery life, battery performance and/or vehicle fuel economy.