Fuel Cell Air Compressor Regenerative Braking Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell vehicles face challenges in maximizing regenerative braking efficiency when the high voltage battery is fully charged, as it can lead to overvoltage and potential damage to the fuel cell system.
Innovation Solution
An air compressor control method that senses the state of charge of the high voltage battery and derives an allowable current for regenerative braking using the current consumption of electric or electronic sub-assemblies, preventing overvoltage by restricting the voltage through equations such as Ireg=2Vdc*Idc_e/(3λ*we), and operating the air compressor motor based on this allowable current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regenerative braking is performed when the high voltage battery is fully charged, then fuel efficiency is improved through energy recovery, but overvoltage occurs causing potential damage to the fuel cell system
Solution Approach 1:
The system dynamically changes the operating parameters of the air compressor motor based on battery SOC levels. When the battery is fully charged, the control method adjusts the motor's current and rotation speed to prevent overvoltage while still enabling regenerative braking. This parameter adjustment allows the system to recover energy safely without damaging the fuel cell stack.
Solution Approach 2:
The control method implements dynamic regulation of the air compressor motor's operation based on real-time battery state monitoring. The system transitions between different operating modes (normal operation, regenerative braking, and restricted operation when battery is full) to adapt to changing conditions, ensuring both energy recovery and system protection.
2Use of energy by moving object
If the air compressor motor rotation speed is reduced to enable regenerative braking, then energy recovery is maximized, but the air supply to the fuel cell stack may be insufficient
Solution Approach 1:
The system dynamically adjusts the air compressor motor's rotation speed and current based on real-time monitoring of both battery SOC and fuel cell air demand. When regenerative braking is needed, the control method temporarily reduces speed within acceptable ranges, and when air supply becomes critical, it restores motor operation to maintain proper air flow to the fuel cell stack.
Solution Approach 2:
The control method employs feedback mechanisms by continuously monitoring battery SOC levels and adjusting the air compressor motor operation accordingly. The system uses the derived allowable current based on SOC to regulate motor current, ensuring that regenerative braking occurs only when it won't compromise air supply requirements or cause overvoltage 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
This method improves fuel efficiency and prevents overvoltage, thereby enhancing the durability of the vehicle by maximizing regenerative braking energy while ensuring safe operation of the fuel cell system.
Implementation Method 1
a portion of kinetic energy generated by a driving speed of a vehicle is used for driving a generator. Thus, kinetic energy for restarting a vehicle is stored and at the same time, electric energy is generated
Implementation Method 2
power to drive the vehicle is obtained by continuously generating electric energy by an electrochemical reaction, such as an electrolysis reverse reaction of water
Data Source
AI summary
An air compressor control method for a fuel cell vehicle is provided. The method includes sensing variation information of a rotation speed of an air compressor motor and sensing a state of charge (SOC) of a high voltage battery by the fuel cell controller when the rotation speed of the air compressor motor is reduced. An allowable current from regenerative braking of an air compressor is derived using current consumption of an electric or electronic sub-assembly for a fuel cell vehicle in response to determining that the SOC exceeds a predetermined level of the SOC. The air compressor motor is then operated based on the allowable current from regenerative braking by an air compressor controller.