Design and control of a DC-DC converter

Abstract

This project presents the design and control of a DC-DC converter, focusing on developing an educational gadget used for teaching purposes in class EE4207 Control Engineering and Desing module. A comparison between two methods of control, analogue and digital, implemented on a buck converter will be examined.

Starting with the hardware improvements to the existing DC-DC converter gadget, the PCB was redesigned to integrate analogue and digital controls onto a single platform. Subsequently, MATLAB was utilised for the design and simulation of a linear PI controller that was intended to run on two separate microcontrollers, a Raspberry Pi Zero and an STM32 microcontroller. The goal of having an additional microcontroller, like the STM32, was to provide a secondary microcontroller option as a form of performance benchmarking, which also allowed for investigation of how two different microcontrollers would operate with their significant differences in their architecture. A robust firmware was developed for the STM32 microcontroller along with a GUI for real-time parameter adjustment and system performance evaluation.

Performance assessments revealed that the digitally controlled system using the STM32 microcontroller achieved faster control loop speeds and better load regulation compared to the analogue controller. The ease of parameter adjustments gives digital control a clear advantage over its analogue counterpart. A smoother and more stable response under various load conditions was also observed by the digital controller, which validated its superiority in various applications like a buck converter.

This study not only contributes to the academic literature by bridging a research gap with a practical educational tool but also showcases the benefits of digital control in DC-DC converters. The final system promises to enhance the learning experience by providing a hands-on approach to understanding control systems and their real-world applications to students in EE4207.