Vehicle Battery Thermal Control for Fast-Charging Temperature Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric vehicles and hybrid vehicles face challenges in optimizing battery temperature control during charging, particularly during fast charging, which affects charge capacity and time, necessitating a method to achieve optimal temperature management for efficient charging.
Innovation Solution
A vehicle thermal management system integrating a HVAC subsystem, battery cooling subsystem, and battery chiller to adjust coolant temperature by measuring battery state and ambient conditions, using refrigerant and coolant loops to optimize temperature control for charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a water-cooled battery cooling system is adopted to extend all electric range and improve battery performance, then energy density and battery durability are improved, but device complexity increases due to integration with HVAC subsystem, battery cooling subsystem, and battery chiller
Solution Approach 1:
The patent merges the battery cooling subsystem with the HVAC subsystem by integrating the battery chiller into the existing refrigerant loop. The battery cooling subsystem shares components such as the compressor, condenser, and expansion valve with the HVAC system, allowing simultaneous cooling of both the battery and passenger compartment while reducing overall system complexity compared to separate independent cooling systems.
Solution Approach 2:
The battery chiller serves multiple functions: it cools the battery during fast charging operations, provides cooling capacity for the passenger compartment through the HVAC system, and can operate independently or in conjunction with other cooling modes. This multi-functionality allows a single system to address multiple thermal management requirements.
2Productivity
If fast charging is performed to reduce charging time, then productivity is improved, but battery temperature increases which requires active cooling to maintain optimal temperature
Solution Approach 1:
The system performs preliminary cooling actions before and during fast charging by activating the battery chiller in advance to pre-cool the battery. The controller monitors battery temperature and SOC in real-time, and activates cooling modes before temperature reaches critical levels, preventing overheating during high-rate charging operations.
Solution Approach 2:
The system employs feedback control by continuously monitoring battery temperature and state of charge (SOC) during charging operations. The controller adjusts the cooling capacity of the battery chiller based on real-time temperature measurements, increasing cooling output when temperature rises during fast charging and reducing it when temperature is within optimal range, thereby maintaining optimal charging conditions.
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 system effectively adjusts battery temperature for optimal charging, enhancing charge capacity and reducing charging time by integrating HVAC and battery cooling subsystems to manage temperature dynamically.
Implementation Method 1
a battery chiller transferring heat between the refrigerant circulating in the refrigerant loop and the battery-side coolant circulating in the battery coolant loop
Data Source
AI summary
A method for controlling a temperature of a battery using a vehicle thermal management system including an HVAC subsystem including a refrigerant loop through which a refrigerant circulates, a battery cooling subsystem including a battery coolant loop through which a battery-side coolant circulates, and a battery chiller transferring heat between the refrigerant circulating in the refrigerant loop and the battery-side coolant circulating in the battery coolant loop may include: measuring a battery temperature and SOC value of the battery when charging the battery; determining a target temperature optimized for charging of the battery based on the measured battery temperature and SOC; and adjusting a temperature of the battery-side coolant by controlling at least one of the HVAC subsystem and the battery cooling subsystem according to whether the HVAC subsystem operates, a result of comparing an ambient temperature and the battery temperature, and a result of comparing the battery temperature and the target temperature.