Fuel Cell Stack Uphill Control for Speed Limitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell vehicles face limitations in vehicle speed on uphill roads due to temperature rises and water content decreases in the fuel cell stack, leading to reduced power generation and potential speed limitations, especially when battery state of charge is low.
Innovation Solution
Implementing a control method that determines if the vehicle is traveling on an uphill road and performs temperature reduction and humidification controls before reaching the incline, reducing the fuel cell stack temperature and increasing water content to maintain optimal conditions, thereby preventing speed limitations and protecting the fuel cell stack.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the generated power of the fuel cell stack is increased to suppress decrease in vehicle speed during traveling on an uphill road, then the vehicle speed is maintained, but the temperature of the fuel cell stack rises and the water content decreases
Solution Approach 1:
The control device performs preliminary cooling of the fuel cell stack before the vehicle enters an uphill road section. By detecting upcoming uphill sections using navigation information and performing temperature reduction control in advance, the system prepares the fuel cell stack to handle increased power demands without excessive temperature rise or water content decrease during uphill travel.
2Speed
If the generated power of the fuel cell stack is increased to suppress decrease in vehicle speed during traveling on an uphill road, then the vehicle speed is maintained, but the water content of the fuel cell stack decreases
Solution Approach 1:
The control device performs preliminary humidification of the fuel cell stack before the vehicle enters an uphill road section. By increasing water content in advance based on detected uphill sections, the system ensures adequate water content is available to handle the increased electrochemical reactions during uphill travel, preventing membrane drying and performance degradation.
3Reliability
If the SOC of the battery becomes equal to or less than a predetermined amount, then the electric power supplied from the battery to the motor cannot be increased, but the vehicle speed may still be limited
Solution Approach 1:
The control device performs preliminary cooling and humidification of the fuel cell stack before uphill sections, enabling the fuel cell to generate additional power when battery SOC is low. This advance preparation allows the fuel cell to operate more efficiently during uphill travel, compensating for limited battery power availability and preventing vehicle speed limitation.
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 prevents vehicle speed limitations on uphill roads while protecting the fuel cell stack by maintaining temperature and humidity margins, reducing the likelihood of current limitations and ensuring stable power generation.
Implementation Method 1
the power generation cells generating electric power by an electrochemical reaction of a fuel gas and an oxygen-containing gas
Implementation Method 2
the temperature reduction control is a control of reducing a temperature of the fuel cell stack
Implementation Method 3
the humidification control is a control of increasing a water content of the fuel cell stack
Data Source
AI summary
An ECU of a fuel cell vehicle determines whether the vehicle travels on an uphill road or not. When determining that the vehicle travels on the uphill road, the ECU performs at least one of a temperature reduction control for reducing the temperature of a fuel cell stack and a humidification control for increasing the water content of the fuel cell stack, by the time the vehicle reaches the uphill road.