Loss Analysis And Thermal Design Of The Pfc Module Study

In the dissertation, we analyzed and compared with the loss mechanism of the Zero-Voltage-Transition PWM soft switching and classical PWM circuit. then gave a more detail calculation. By applying optimum method in ZVT-PFC power circuit, assistant commutation circuit and inductor design, we selects reasonable circuit configuration and parameters , and obtain PFC power module which has a minimum weight. The data obtained from a 1.5kW Zero-Voltage-Transition(ZVT) single phase Power-Factor-Correction (PFC) rectifier with the PFC IC UC3 854 ,it supports the conclusions results. Secondly, by Studying the magnetic character under the high-frequent pulse voltages, a practical method is presented for computing high-frequency ferrite core losses in the magnetic component for different duty cycles pulse voltages waveforms. The optimum distribution of the core and copper loss also can be deduced form the minimum loss object mode. By analyzing the thermal circuit diagram, we get a thermal resistance expression of inductor. A design procedure for optimum design of a high-power, high-frequency inductor is presented. This procedure is based on a given difference in temperature. AT last, the cooling way is given according to the specifications and used conditions of the Module power Supply. By calculating thermal resistance, we select suitable sink. A process of thermal design to assure the reliable operation of Module Power Supply in the temperature rating is presented ,practical results show good agreement with the theory.