Design And Implementation Of LLC Resonant Converter Based On PFC

Driven by the rapid development of power electronics technology, a large number of electronic devices come into use, and the power factor, the efficiency, the bulk and the reliability of the switching power supply has the higher demanding.Compared with the traditional PWM converter, the LLC resonant power has the advantages of the simple structure, high switching frequency, high efficiency, low switching stress.In order to provide DC power to the auxiliary equipment of a device, account the efficiency and the power factor, this topic is expected to develop a AC/DC power module which has network voltage input and 40V/10 A DC, the output voltage ripple is less than 70 mV, the power factor is not less than 0.95 and the typical efficiency is greater than 90%.First of all, through the consult massive material this paper analyzes the development trend of the power factor correction technique and the resonant power supply at home and abroad, analyzes and compares the resonant converter, and determines to use the one cycle control PFC and LLC resonant converter as the main circuit topology, then the schemes of the whole system is determined.Secondly, the one cycle control PFC is investigated,the operating modes and the steady state of the LLC resonant converter is investigated based on theory of fundamental,the necessary condition of soft switching is also determined and make sure the design process of the LLC resonance parameters.Thirdly, the power circuit for power factor correction is designed in detail. According to the resonant parameters of the converter, the magnetic integration of the transformer is carried out by using the area product method and he power circuit for LLC resonant converter is designed in detail. The control circuit of is designed by using the chips UCC28019 and UCC25600.Finally, the PCB is designed including the thermal design of PCB,then the device is welded to form a power supply prototype,the overall test results of the prototype show that every indicator meets the design requirements.