Dynamic Battery Charge Threshold for Cold-Weather Warm-Up
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Solution Overview
Problem
Existing battery temperature control devices for electric vehicles do not effectively manage battery temperature in cold conditions, leading to reduced usable power and prolonged charging times due to a fixed battery charge state setting that prevents warm-up when the charge state is below a certain threshold, causing further temperature drops and decreased power output.
Innovation Solution
A battery temperature control device that dynamically adjusts the battery charge state setting to permit warm-up by a battery-driven heater when the battery is in a charge-capable state, ensuring the battery can travel to a charging facility and maintaining a sufficient charge current, thereby avoiding further temperature decreases and shortening charging time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery charge state setting is fixed to prevent warm-up when charge state is below threshold, then battery charge state is maintained, but battery temperature further lowers and usable power decreases
Solution Approach 1:
The battery charge state setting is changed from a fixed value to a dynamically adjustable value. When the battery is in a charge-capable state (can reach charging facility), the setting is lowered to permit warm-up even at low charge states. When not charge-capable, the setting is raised to maintain charge state. This dynamic adjustment resolves the contradiction by adapting the charge state threshold to the vehicle's charging situation.
Solution Approach 2:
The control system changes the parameter of battery charge state setting based on the battery state (charge-capable or not). By modifying this control parameter dynamically rather than keeping it fixed, the system can permit warm-up operations when appropriate (when charge-capable) while maintaining charge state when necessary (when not charge-capable), thus resolving the power vs. reliability contradiction.
2Reliability
If the battery charge state setting is fixed to prevent warm-up when charge state is below threshold, then battery charge state is maintained, but charging time becomes longer due to decreased charge current
Solution Approach 1:
The system dynamically adjusts the battery charge state setting based on whether the vehicle is charge-capable. When charge-capable, the setting is lowered to enable warm-up operations that increase charge current and reduce charging time. When not charge-capable, the setting is raised to maintain charge state. This resolves the contradiction between maintaining charge state and minimizing charging time.
Solution Approach 2:
By changing the battery charge state setting parameter dynamically based on charging capability status, the system enables conditions for fast charging (warm-up with large charge current) when appropriate, while preserving charge state when necessary, thus resolving the time loss contradiction.
3Power
If the battery charge state setting is lowered to permit warm-up, then battery temperature increases and usable power increases, but battery charge state may decrease
Solution Approach 1:
The system applies different charge state settings for different local conditions (charge-capable vs. not charge-capable). When charge-capable, a lower setting is applied locally to permit warm-up and increase power. When not charge-capable, a higher setting is applied to maintain charge state. This localized approach resolves the contradiction between power and charge state quantity.
Solution Approach 2:
The battery charge state setting parameter is changed based on the vehicle's charging capability status. This parameter change enables the system to permit warm-up operations (increasing power) when charge-capable, while maintaining charge state when not charge-capable, thus resolving the contradiction between power output and charge state quantity.
4Temperature
If a battery-driven heater is used for warm-up, then battery temperature increases, but energy is consumed from the battery
Solution Approach 1:
The system performs preliminary assessment of the vehicle's charge capability before permitting warm-up operations. By checking whether the vehicle can reach a charging facility with sufficient charge state, the system ensures that energy-consuming warm-up operations are only initiated when the battery has sufficient energy reserves or external charging is available, thus resolving the contradiction between temperature increase and energy consumption.
Solution Approach 2:
The battery charge state setting parameter is dynamically adjusted based on charging capability, which indirectly controls energy consumption. When the setting is lowered to permit warm-up, it is because the system has determined the vehicle is charge-capable, meaning energy consumption for heating will be compensated by upcoming charging, thus resolving the energy consumption contradiction.
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
The solution allows for immediate battery warm-up when the battery is in a charge-capable state, preventing further temperature drops, increasing usable power, and ensuring a large charge current, thus reducing charging time.
Implementation Method 1
warming up the battery by a battery-driven heater
Data Source
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AI summary
At a timing of time t1, battery temperature Tbat lowers to Tbat_start and a warm-up request occurs, SOC at this time is a level, like time t2, which allows a vehicle to travel by itself up to a battery charging facility and allows a battery charger to be connected to the battery charging facility. Since a warm-up permission judging value is set to SOCs_low that is substantially 0 at time t1, in response to judgment of "SOC ≧ SOCs_low (≒ 0)", warm-up of the battery is carried out from time t1 as shown by a solod line, then Tbat can be increased from time t1. A battery charge time can be thus shortened. With this, in order that the battery does not freeze while the battery is unused, a control that warms up the battery by a battery-driven heater is performed while shortening the battery charge time.