Closed loop control of fuel cell with buck converter

Closed loop control of fuel cell with buck converter

Setting Up the MATLAB Environment

Creating the Simulink Model

1. Open MATLAB: Start by launching MATLAB on your computer.

2. Create a New Model: Go to the Home tab, click on "New," and select "Simulink Model" to open a blank model.
   

Adding the Fuel Cell

1. Navigate to Simscape: In the Simulink Library Browser, go to the Simscape section.

2. Select Power Systems: Within Simscape, choose "Power Systems," then "Electrical Drives," and finally "Sources."

3. Add Fuel Cell Stack: Drag the "Fuel Cell Stack" block into your model.

Configuring the Fuel Cell

1. Double Click the Fuel Cell Block: Open the parameters window.

2. Select Preset Model: Choose the "Proton Exchange Membrane Fuel Cell" with a rating of 1.26 kW and 24 V DC.

3. Apply Settings: Click "Apply" and then "OK" to confirm your choice.

Implementing the Buck Converter

Adding Converter Components

1. Capacitor: Add a capacitor block for input capacitance.

2. Switch: Search for and add an IGBT (Insulated Gate Bipolar Transistor) block.

3. Diode: Insert a diode block into your model.

4. LC Filter: Include an LC filter block. Set the inductance (L) and capacitance (C) as required.

Connecting the Components

1. Connect the Fuel Cell to the Converter: Link the fuel cell to the input side of the buck converter.

2. Add a Load: Incorporate a resistive load block.

3. Current Measurement: Use a current measurement block to monitor the load current.

4. Voltage Measurement: Add a voltage measurement block to measure the load voltage.

Designing the Closed-Loop Control System

Setting Up the Controller

1. Add Reference Voltage: Use a constant block to set a reference voltage of 12 V.

2. Subtractor Block: Connect the reference voltage to a subtractor block to compare it with the actual voltage.

3. PID Controller: Implement a PID controller block to regulate the output voltage.

Generating Pulse Signals

1. Pulse Generator: Use a PWM (Pulse Width Modulation) block to generate the control signals for the buck converter.

Simulation and Results

Running the Simulation

1. Set Simulation Parameters: Adjust the switching frequency and other simulation parameters as needed.

2. Execute the Simulation: Run the simulation and observe the results.

Analyzing the Results

1. Load Voltage: Ensure that the output voltage at the load is maintained at 12 V.

2. Load Current and Power: Verify the current and power at the load to ensure they match the expected values.

3. Input Voltage and Current: Check the input voltage and current from the fuel cell.

Conclusion

In this post, we demonstrated how to set up a closed-loop control system for a fuel cell with a buck converter using MATLAB. This setup helps in maintaining a stable output voltage while adjusting for any variations or faults in the system.