Speaker: Yichao Liu, Shanghaitech University
Time: 13:30-14:30 , Oct.22
Location: SIST 1C 101
Host: Prof. Junrui Liang
Abstract:
Since LLC resonant converters are endowed with the characteristics of high conversion efficiency and power density, they are widely harnessed in a variety of industrial electronics. An accurate model of the LLC converter is the prerequisite of the following research contents like efficiency optimization and frequency modulation. Generally, the steady-state analysis of LLC converters can be divided into two parts: frequency domain method and time domain method. The peak gain’s value and position is of vital importance in the process of designing the parameters of LLC converters. The Extended Impedance Method (EIM), a frequency domain method, is applied on the peak gain and steady-state analysis of LLC converters. This method provides a brand-new view of analyzing LLC converters because it starts from the perspectives of the circuit components rather than the whole circuit equations, thus enabling the designers not to consider the multiple operation works in time domain as well as improve the accuracy of peak gain value in frequency domain. In order to verify the efficiency and accuracy of EIM, the results of EIM are compared with the ones of both simulation and experiment. In our simulation and experiment, the full load power is 75W with constant output voltage of 30V. The input voltage varies from 80V to 140V. The nominal voltage and resonant frequency are 120V and 200kHz respectively. The relative error of voltage is 0.3% and simulation time of one case is around 2 second.
Bio:
Mr. Yichao Liu has received his B.E. degree in electronic engineering from Donghua University in June 2019. He is now working towards his master degree at ShanghaiTech University, China. His research interests include the circuit dynamic simulation algorithm.