Fuel Cell Hydrogen Supply Valve Control for Pressure Tracking
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Solution Overview
Problem
Existing fuel cell systems face challenges in maintaining target pressure in the hydrogen supply line, leading to increased duty instruction amplitude and control overshoot during high-output operations and purge events.
Innovation Solution
A fuel supply control system that uses a base duty instruction for the hydrogen supply valve based on the required hydrogen flow rate and power generation state, combined with a feedback duty instruction to correct pressure deviations, ensuring precise control and preventing overshoot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PWM duty control of hydrogen supply valve is used to control flow rate, then the hydrogen supply can be adjusted to follow target pressure, but the duty instruction amplitude increases and control overshoot occurs during high-output operation and purge events
Solution Approach 1:
The control method segments the duty instruction into two independent components: a base duty instruction calculated from the required hydrogen flow rate and power generation state, and a feedback duty instruction calculated from pressure deviation. This segmentation allows each component to address specific control requirements independently, preventing the amplitude and overshoot problems caused by unified PWM control.
Solution Approach 2:
The control method introduces a feedback mechanism where the feedback duty instruction is calculated based on the deviation between actual and target pressure. This feedback component dynamically adjusts the total duty instruction to correct pressure deviations without causing overshoot, while the base duty instruction handles the primary flow rate requirement.
2Productivity
If target pressure is increased during high-output operation, then hydrogen supply demand is met, but duty instruction amplitude increases causing control issues
Solution Approach 1:
By segmenting the duty instruction into base and feedback components, the system can scale the base duty instruction proportionally with power generation output requirements without causing amplitude-related control issues. The feedback component remains bounded and stabilizes the control signal.
Solution Approach 2:
The control method changes the parameter representation from a single duty cycle percentage to a two-component structure (base duty + feedback duty). This allows the system to accommodate varying power generation demands by adjusting the base component while maintaining stable feedback control, preventing duty amplitude from causing control problems.
3Reliability
If purge valve is opened to maintain hydrogen concentration, then impurities are removed, but pressure disturbance occurs causing control overshoot
Solution Approach 1:
The control method applies preliminary anti-action by using the feedback duty instruction to anticipate and counteract the pressure disturbance caused by purge valve opening. The feedback component calculates the required adjustment based on pressure deviation and applies it before significant overshoot can occur, maintaining pressure stability during purging operations.
Solution Approach 2:
The feedback mechanism continuously monitors pressure and dynamically adjusts the feedback duty instruction to compensate for disturbances from purge operations. This allows the system to maintain hydrogen concentration through purging while preventing pressure instability and control overshoot through real-time correction.
Data Source
AI summary
Disclosed are a system and a method for fuel supply control for a fuel cell. The system includes a fuel supply line, a fuel supply valve, a base duty calculator configured to estimate a required supply amount of a fuel gas required for the fuel supply line on the basis of a power generation state of the fuel cell and to calculate a base duty instruction to open the fuel supply valve on the basis of the estimated required supply amount, and a valve controller.