Control and topologies for power converters: I . One-cycle control of three-phase power converters. II . New resonant dc-dc converters

Part I. Research and applications of PFC rectifiers, APF, STATCOM, and GCI using Voltage-Source Inverters (VSI) have attracted a great attention due to the increased energy awareness and power-quality concern in the global. Previous theory and experiments have demonstrated that One-Cycle control is capable of controlling all above converters, featuring excellent performance, simple circuitry, and low cost. In light of the great advantages of OCC based controller, in this thesis it has been further studied and extended to control four-quadrant power flow, to work at unbalance conditions, and to control multi-level VSIs.; The study on the four-quadrant power flow results a universal vector-control method, which can be realized with a simple universal circuit. Moreover, the unified One-Cycle Controller can realize the modular design of PFC, APF, STATCOM, zero-load operation of PFC rectifier, natural bidirectional rectifier/inverter, and three-phase converters with combination of P and Q output.; The study on the converter's unbalance operation is implemented by an three-phase APF, and the results indicate that (1) when the line voltage is unbalanced, the line currents will be sinusoidal and follow the non-zero sequence components of the line voltage; and (2) when the load is unbalanced, e.g. one phase is disconnected, the APF with OCC control can automatically generate harmonic and unbalanced reactive currents to cancel those from nonlinear unbalanced load to keep the line currents balanced and with unit-power-factor.; The study on three-phase three-level power converters results several circuit level decoupling methods, and each decoupling strategy has its eminent characteristics that can be tailored to a variety of needs. Study also proves that in the proposed APFs, the voltage on the two output capacitors can be automatically balanced.; Part II. The development of modern semiconductor manufacturing technology brings forward stringent demands to the new generation Voltage Regulation Module (VRM) for microprocessors. To satisfy the requirements, the most suitable converter topology's features are sketched in this thesis, then based on the sketched features a multiphase LLC series resonant converter is proposed. A systematic theoretical study indicate that the proposed multiphase LLC resonant converter features: (1) Zero voltage switching for both inverter and rectifier switches; (2) Wide load range; (3) Limited frequency range; (4) Fast dynamic response; (5) High efficiency; and (6) Automatic current sharing ability. All of these features ensure that the proposed multiphase LLC resonant converter is a good VRM candidate for next generation microprocessors. (Abstract shortened by UMI.)...