Fuel Cell Stop Control Using Battery Capacity and Stop Duration
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Solution Overview
Problem
Frequent vehicle stops negatively affect the durability and lifetime expectancy of fuel cell systems in fuel cell electric vehicles (FCEVs) due to frequent deactivation and operation at low power levels, leading to fuel cell performance degradation.
Innovation Solution
A computer system is implemented to control the fuel cell system during vehicle stops by calculating the storage capacity of the vehicle battery, determining the maximum feasible fuel cell power output, and controlling the charging mode based on this power output to minimize degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the fuel cell system is deactivated during vehicle stops, then energy consumption is reduced, but fuel cell durability and lifetime expectancy deteriorate due to frequent deactivation and low power operation
Solution Approach 1:
The control system performs preliminary action by determining the stop duration before the vehicle stop occurs and calculating the required fuel cell power output in advance. This allows the fuel cell to be operated at an optimal power level during the stop period rather than being deactivated, thereby maintaining durability while managing energy consumption efficiently.
Solution Approach 2:
The system dynamically adjusts the fuel cell power output based on the predicted stop duration and battery state of charge. The control strategy adapts the power level in real-time, operating at higher power for longer stops to maintain durability, and adjusting for shorter stops, thereby resolving the contradiction between energy consumption and durability.
2Reliability
If the fuel cell operates at high power output during vehicle stops, then fuel cell durability is maintained, but battery charging capacity is reduced due to limited storage capacity during the stop period
Solution Approach 1:
The control system uses feedback by continuously monitoring the battery state of charge and comparing it with the target state of charge. Based on this feedback, the system calculates the maximum feasible fuel cell power output that will charge the battery to the target level without exceeding storage capacity, thereby balancing durability maintenance with charging capacity constraints.
Solution Approach 2:
The system changes operational parameters by adjusting the fuel cell power output level based on the calculated stop duration and battery storage capacity. This parameter adjustment ensures the fuel cell operates at an optimal power level that maintains durability while respecting the battery's charging capacity limitations during the stop period.
3Quantity of substance
If the fuel cell power output is limited during vehicle stops, then battery charging capacity is preserved, but fuel cell degradation increases due to operation at low power levels
Solution Approach 1:
The control system performs preliminary calculation of the optimal fuel cell power output based on the predicted stop duration and battery state of charge before the stop begins. This preliminary action determines the minimum power level required to maintain fuel cell performance while achieving the desired battery charging capacity, avoiding both over-limitation and excessive power consumption.
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 effectively predicts and manages the fuel cell system's power output during stops, thereby improving efficiency, lifespan, responsiveness, safety, and adaptability to different fuels and loads, while reducing fuel cell degradation.
Implementation Method 1
a fuel cell electric vehicle, hereinafter abbreviated FCEV, is a vehicle operating by using a fuel cell stack that converts hydrogen into electricity
Implementation Method 2
The vehicle powertrain also includes a vehicle battery that can be charged from the fuel cell stack or from the grid
Data Source
AI summary
A computer system for controlling a fuel cell system during a vehicle stop of a vehicle is described. The computer system has processing circuitry configured to obtain a stop duration of the vehicle stop; calculate a storage capacity of a vehicle battery of the vehicle as a difference between a current state of charge of the vehicle battery and a target state of charge of the vehicle battery at the end of the stop duration; calculate a battery charging energy for the vehicle battery based on the storage capacity; determine a maximum feasible fuel cell power output of the fuel cell system for charging the vehicle battery using the battery charging energy; and control a charging mode of the fuel cell system based on the maximum feasible fuel cell power.