Modeling And Simulation Of Resonant Converter

Resonant converter is always controlled by PFM and the switch is always operated in ZVS or ZCS state, so the switch loss is insignificant and the efficiency of the converter is high. With due consideration of above, the converter could be operated in high switch frenquency as result of reduction of volume of inductance and capacitance in low-pass filter network. However, the analysis of main circuit of resonant converter is complicated, and the small signal model is unanalytic. Compared with PWM control technique, the PFM control technique applied in resonant converter became hot research topic.Based on three paper and a book named 'model and control of switch power supply' written by me and my teacher, PFM control technique of LCC resonant converter is researched in this paper.The basic knowledge of resonant converter is introduced in 1^st chapter.Based on the 1^st chapter, the operation of LCC resonant converter is analyzed and the steady state model is acquired in the 2^st chapter.In the 3^st chapter, The design of main circuit, the simulationof control IC—UC3861 in pspice and the open-loop simulation of the LCC resonant converter is accomplished in the 3^st chapter. In the end, using the modeling form control to output of LCC converter and matlab software, the bode plot of LCC resonant converter from control to output in the worst state is obtained step by step.In the 4^st chapter, after compensation of LCC resonant converter in the same method in PWM converter, the disadvantage is obvious, and the two solutions are proposed, but the all can be proved undoable.The new compensator is proposed in the 5^st chapter and the closed-loop simulation of LCC resonant converter is attained.The record, step and relevant waveforms of experiment is in the 6^st chapter,...