Available at: https://digitalcommons.calpoly.edu/theses/2872
Date of Award
6-2024
Degree Name
MS in Electrical Engineering
Department/Program
Electrical Engineering
College
College of Engineering
Advisor
Jason Poon
Advisor Department
Electrical Engineering
Advisor College
College of Engineering
Abstract
Power electronics possess forms of non-ideality due to the nonlinearity present in physical switches. These switches are driven with pulse width modulation (PWM), which properly down-converts or up-converts based on converter topology. When these switches turn on or off, they introduce the main proponent of efficiency loss: harmonics. This becomes a nonlinear optimization problem with many converters. The solution proposed in this thesis is an analog/digital hybrid computer that utilizes the speed of analog computation and the accuracy of digital computing together. A Plexim RT Box provides the programmability needed for algorithms, while the analog circuit provides low-power, high-speed computation in order to provide the proper switching angle to minimize harmonics. This study explores optimization techniques for PWM harmonic elimination by implementing a hybrid computer that simulates harmonics and calculates solutions to the nonlinear optimization problem. Specifically, the analog computer handles the gradient flow dynamics of harmonic elimination by utilizing nonlinear programming and the KKT conditions. The analog computer is optimized by exploring higher-slew-rate operational amplifiers and observing their effects on convergence. All results are consistently compared to an LTSpice simulation to ensure the accuracy and stability of the physical analog computer.