In MATLAB, the design of a Proportional-Integral (PI) controller for a Buck Converter can be facilitated using the System Identification Toolbox. This toolbox enables the modeling and analysis of dynamic systems from experimental data, allowing engineers to identify the transfer function of the Buck Converter under different operating conditions. By analyzing the identified model, suitable controller parameters can be determined to achieve desired performance specifications such as stability, transient response, and disturbance rejection. The PI controller design process involves tuning the proportional and integral gains based on the identified system dynamics to ensure robust and efficient control of the Buck Converter. Through the integration of the System Identification Toolbox within MATLAB, engineers can streamline the design and implementation of PI controllers for Buck Converters, thereby optimizing power conversion efficiency and performance in various applications.