Modeling and control of voltage-fed phase-controlled resonant converters

Resonant converters have been widely used in power supplies due to their fast transient response and inherent soft-switching characteristics. However, modeling and control of resonant converters has long been a challenge due to the switching operation and large number of reactive components in their circuits. This dissertation is aimed at modeling and control of a class of the most popular resonant converters, voltage-fed resonant converters. The high-order Phase-Controlled Series-Parallel Resonant Converter (PC SPRC) is used as an example throughout the dissertation.; To obtain a tractable model for the high-order PC SPRC, extended describing function and circuit decomposition methods are used. The resulted non-linear PC SPRC model is linearized and reduced into a third-order model by employing balanced truncation technique. A digital controller is designed for the PC SPRC based on the reduced model. A direct digital controller design procedure is presented. The controller is implemented with a DSP and its performance is shown for the first time.; Aimed at providing an effective and time saving solution for the control of high-order resonant converters, a Fuzzy Logic Controller (FLC) is designed for the PC SPRC for the first time. Since the FLC is knowledge based, no strict mathematical model is needed in FLC design. Thus, the developing period for a new product can be greatly reduced by using FLC.; Finally, a PC SPRC designed in this dissertation is applied to an Electrostatic Precipitator (EP). This is the first time for the PC SPRC to be used in such a high power high voltage application. By using switch-mode power supply instead of the traditional line-frequency power supply, both the size and power losses of the unit are greatly reduced.