EV Battery Charging Timing for Thermal Preconditioning
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Solution Overview
Problem
Electric vehicle traction batteries often require external heating to achieve optimal operating temperatures, which consumes additional energy and reduces efficiency, as charging typically occurs outside the desired temperature range and relies on resistive heating or heat pumps.
Innovation Solution
A control system that calculates a charging start time based on the journey start time, target battery charge level, and target temperature range, using the charging process to heat the battery to the optimal range, thereby reducing reliance on external heaters and utilizing thermal energy generated during charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If external heating devices or heat pumps are used to heat the battery to optimal operating temperature, then the battery can operate within the desired temperature range, but additional energy is consumed and efficiency is reduced
Solution Approach 1:
The patent converts the harmful heat generated during charging (which is typically dissipated as waste) into a beneficial heating source for pre-conditioning the battery. By timing the charging process to occur before the vehicle is needed, the charging-generated heat raises the battery temperature to the optimal operating range, eliminating the need for separate heating devices and reducing overall energy consumption.
Solution Approach 2:
The patent performs the heating action in advance by scheduling the charging process to start before the vehicle is required. The battery is heated to the desired operating temperature through charging before the vehicle is driven, rather than heating it immediately before use. This preliminary charging action ensures the battery is ready for optimal performance when the vehicle is needed.
2Reliability
If charging is performed continuously to maintain battery charge level, then the battery is always ready for use, but the battery may overheat and operate outside the optimal temperature range
Solution Approach 1:
The patent implements periodic charging actions rather than continuous charging. The charging process is activated at specific intervals or triggers (such as when the vehicle is parked and before anticipated use) to raise the battery temperature and charge level. This periodic approach ensures the battery is ready for use while preventing continuous operation that would cause overheating.
Solution Approach 2:
The patent dynamically adjusts the charging process based on real-time battery conditions, including temperature and charge level. The charging rate and duration are modulated to maintain the battery within the optimal temperature range while ensuring adequate charge levels. This dynamic control prevents both overheating and insufficient charging.
3Productivity
If the battery is charged quickly to ensure adequate charge level, then the charging time is reduced, but excessive heat is generated that may exceed the optimal temperature range
Solution Approach 1:
The patent performs charging as a preliminary action before the vehicle is needed, utilizing the time when the vehicle is parked. This allows the charging process to occur at an optimal pace that generates necessary heat without excessive temperature rise, as the charging is not rushed but scheduled during available time windows.
Solution Approach 2:
The patent changes the operational parameters of the charging process by controlling the charging rate and duration based on battery temperature feedback. The charging parameters are adjusted to maintain the battery within the optimal temperature range (15°C to 35°C) while still achieving adequate charge levels, balancing charging speed with temperature control.
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
This approach ensures the battery operates within the desired temperature range at the time of use, enhancing efficiency and reducing energy consumption by leveraging charging-generated heat, thus maintaining optimal performance and extending battery life without the need for additional heating.
Implementation Method 1
During charging, heat is generated in the battery as a function of the current and resistance of the conductive material and the internal resistance of the cells
Data Source
AI summary
A control system (100) for a traction battery (1000) in an electrically powered vehicle. The control system (100) is configured to: receive a journey start time (102) indicative of a time at which the traction battery will be used to power the vehicle; calculate, using the journey start time (102), and in dependence on a target battery charge level (104) and a target battery operating temperature range (106), a charging start time (108) at which to start charging of the traction battery (1000) to: charge the traction battery toward the target battery charge level by the journey start time; and heat the traction battery, due to charging of the traction battery, toward a temperature within the target battery operating temperature range, by the journey start time; and output the determined charging start time (108).