Date of Award
Doctor of Philosophy (PhD)
Electrical, Computer & Energy Engineering
As electrical systems increasingly come to dominate modern life, the power conversion technologies that enable these systems to efficiently connect to one another are becoming increasingly important. With the expanding demand for such technologies in ever diversifying areas, the demands placed on power converters have increased in kind. One major area of research which has attempted to satisfy this demand is in the class of resonant switching converters, such as the series resonant converter. Although high efficiencies with extremely high bandwidths and switching frequencies are possible with these converters, the control complexity needed is sometimes prohibitive.
In this dissertation the theory needed for the modeling and control of one such topology, the dual active bridge series resonant converter (DABSRC), is developed. The results derived are applicable to a wide range of similar topologies as well, greatly increasing their worth. The theory and control techniques based off of the results presented here help make the DABSRC and similar topologies candidate power conversion technologies for even the most demanding application areas.
Using a frequency domain approach for the small signal modeling (SSM), a generalized phasor transformer is first derived. This technique is then applied to the DABSRC in order to demonstrate multi-angle phase shift modulation. The previously derived minimum current trajectories (MCT) are used for power flow control based on the models derived using the generalized phasor transformer. Due to the variability in response characteristics of the DABSRC when operated along the MCT, gain scheduling control of the DABSRC is next developed.
Multi-mode control (MMC) is implemented in gain scheduled converter in order to allow power and voltage regulation with smooth mode transitions. In order to allow zero voltage switching of the DABSRC converter, an in depth analysis of the commonly utilized phase shift modulated (PSM) auxiliary leg technique for zero voltage switching (ZVS) assistance is given. Finally a digital controller is implemented to control as set of prototype DABSRCs. Each converter module is designed to operate with a nominal 500 V input voltage, and an output voltage ranging from 0 V to 600 V with an average power of 1 kW.
Seltzer, Daniel, "Modeling and Control of the Dual Active Bridge Series Resonant Converter" (2014). Electrical, Computer & Energy Engineering Graduate Theses & Dissertations. 88.