Fuel Cell Controller Adaptive Threshold Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell systems, repeated starting and stopping leads to prolonged charging times for secondary batteries, especially during short trips, resulting in insufficient state of charge for the next system start.
Innovation Solution
A fuel cell control device with a controller that performs forced charging of the secondary battery when its state of charge falls below a threshold, adjusting this threshold based on the number of repeated start-stop cycles and battery temperature, and extending the charging time for subsequent cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If charging is performed while the fuel cell system is stopped to secure the needed state of charge, then the secondary battery can be charged, but the charging time becomes excessively long when starting and stopping are repeated frequently
Solution Approach 1:
The patent applies dynamics by making the threshold value adaptive rather than fixed. The controller dynamically adjusts the threshold based on whether a stop command is received within a predetermined period after system start, allowing the charging requirement to change according to operating conditions. This resolves the contradiction by enabling faster charging when frequent start-stop cycles are detected while maintaining adequate charge levels for normal operation.
Solution Approach 2:
The patent changes the parameter of the threshold value based on system operation patterns. When the controller detects that a stop command is received within a predetermined period after start (indicating frequent start-stop cycles), it lowers the threshold from the first predetermined value to the second predetermined value. This parameter change allows the system to reduce charging time in problematic scenarios while maintaining reliability in normal operation.
2Reliability
If the threshold is set high to ensure adequate charge for next start, then reliability is improved, but charging time increases during repeated start-stop cycles
Solution Approach 1:
The threshold is made dynamic by adjusting it based on detected operation patterns. The controller monitors whether stop commands are received within a predetermined period and adapts the threshold accordingly. This dynamic adjustment allows the system to use a lower threshold (second predetermined value) during frequent start-stop cycles, reducing charging time while maintaining adequate charge through the adaptive control strategy.
Solution Approach 2:
The system performs preliminary detection of operation patterns to anticipate charging needs. By detecting whether a stop command occurs within a predetermined period after start, the system can proactively adjust the threshold before charging begins, optimizing the charging process in advance to avoid excessive charging times while ensuring adequate charge levels.
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 significantly shortens the charging time of the secondary battery, ensuring it reaches the necessary state of charge for system operation, even during frequent start-stop scenarios.
Implementation Method 1
a fuel cell system having a fuel cell (14) and a secondary battery (12)
Data Source
AI summary
Under a condition that a command to stop a fuel cell system is received and a state of charge of a secondary battery is equal to or lower than a threshold which is a value obtained by adding a first predetermined value to a lower limit at which electric power required to stop and start the fuel cell system is supplied, forced charging of the secondary battery by a fuel cell is performed until the state of charge reaches the threshold. After the forced charging is performed, in a case where the command to stop the fuel cell system is received within a predetermined period, the controller sets the threshold to a value obtained by adding a second predetermined value lower than the first predetermined value to the lower limit under the condition.