Department of Electrical EngineeringA resonant converter has been widely used in various industrial applications, since it has high power conversion efficiency. The increase of the power density is necessary to obtain high cost-effectiveness and design freedom on the electric products. A high switching frequency operation can be an effective method to obtain the high power density of power converters. In this dissertation, three topic will be discussed to obtain the high power conversion efficiency and the high power density for the resonant converter, as follows:
First, the power stage and feedback loop are designed for the high switching frequency operation. The power stage is designed to obtain the high power conversion efficiency at the high switching frequency operation. In addition, the feedback loop is designed to guarantee the stability.
Second, the control algorithm is proposed to obtain the tight output voltage regulation at the high switching frequency operation. The operational principle and design of control algorithm are analyzed to obtain the tight output voltage regulation.
Third, the spread spectrum technique (SST) will be applied to the resonant converter to reduce the electromagnetic interference (EMI), which can improve the power density with small EMI filter size. In this research, the design constraint to implement the SST on the resonant converter is analyzed to obtain the dual functionality properly. In addition, the control algorithms are proposed to achieve tight output voltage regulation and EMI reduction, simultaneously. All the proposed design considerations and control algorithms are verified with the simulation and experimental results.clos
