Design of PI Controller for Buck Converter Using System Identification Toolbox

Design of PI Controller for Buck Converter Using System Identification Toolbox

Designing the Converter:

We started by establishing the design parameters for the buck converter, including power rating, input voltage, switching frequency, and output voltage requirements. Using design equations, we calculate the values of the inductor, capacitor, and load resistance necessary for the buck converter's operation.

Creating the Converter Model: After determining the design parameters, we proceed to create the buck converter model in MATLAB. This involves assembling the components of the converter, such as the DC source, IGBT (Insulated Gate Bipolar Transistor), diode, inductor, capacitor, and load resistor, based on the calculated values.

Simulation and Analysis: Once the converter model is constructed, we simulate its behavior to observe the input and output voltages. By changing parameters such as input voltage and load resistance, we analyze the converter's response under different operating conditions. We note that without a controller, the output voltage may fluctuate with changes in input voltage or load.

Designing the VA Controller: To stabilize the output voltage of the buck converter, we design a VA controller using MATLAB's System Identification Toolbox. We collect input-output data from the converter model and use it to estimate the transfer function of the system. From the transfer function, we derive the parameters for the proportional (KP) and integral (KI) components of the VA controller.

Implementing the VA Controller: With the parameters obtained from the transfer function, we implemented the VA controller in the buck converter model. The VA controller regulates the output voltage by adjusting the duty cycle of the converter based on the input voltage and load conditions.

Validation and Testing: We validate the performance of the VA controller by simulating the buck converter model with varying input voltages and load resistances. Through simulation, we observe that the output voltage remains stable at the desired level, demonstrating the effectiveness of the VA controller in regulating the converter's output.

Conclusion: In conclusion, the design and implementation of a VA controller using MATLAB's System Identification Toolbox offer a robust solution for stabilizing the output voltage of a buck converter. By leveraging system identification techniques, we can design controllers tailored to specific system requirements, ensuring reliable operation of power electronic systems.