Closed Loop Digitally Controlled Power Supply Analysis and Design with Register Level Coding Emphasis

Abstract

There are several different knowledge skills involved in completing a working digitally controlled power supply. The skills involved are power supply converter design, average power supply modeling, loop compensation techniques, frequency response analysis and stability criteria checks. These skills are covered in most Power Electronics and Linear Control courses. Insertion of digital control requires additional skills: the conversion of the analog control loop to a digital control loop through Z-transforms and modeling of the analog power supply with the digital compensation in the feedback loop. Actual implementation of the power supply with digital control in hardware requires learning microcontroller programming.Analysis and Design of the digital closed loop control using a microcontroller is the focus of the course presented in the paper. Many digital control and microcontroller programming courses are not giving the student the tools to program the digital control from scratch. Previous courses use code generating tools or pre-made libraries to handle a lot of the programming functions. This teaching method is fine for an overall example, but it leaves the student with the skill to only repeat the course example and not develop a digital control program on their own. The student is left with a steep learning curve to use a microcontroller to control different power supplies or use the digital control in another application. This course will teach microcontroller register level programming integrated with the design of a digital control loop for a power supply.