A High Step-Up Isolated Soft-Switching DC-DC Converter with Pulse Frequency Modulation
Zhang Zhiguo1,2, Liu Junliang2, Guo Qiang1, Chen Yan1
1. Energy Internet Engineering Research Center of Chongqing City Chongqing University of Technology Chongqing 400054 China; 2. College of Automation Chongqing University of Posts and Telecommunications Chongqing 400065 China
Abstract:A high step-up isolated soft-switching DC/DC converter with pulse frequency modulation (PFM) was presented in this paper. The converter integrates a flyback converter with active clamp and similar voltage multiplier cells, and all the transistors have soft-switching. The structure of this proposed converter is simple and easy to achieve high voltage gain. At the same time, compared with the pulse width modulation (PWM) mode, the control mode of PFM modulation further reduces the power tube on the current stresses, which helps to improve the converter’s efficiency. The operation principles and characteristics of the proposed converter were analyzed in detail, and the two control strategies were compared. Finally, a 160W, 45V/380V laboratory prototype circuit was implemented to verify the effectiveness and accuracy of the theoretical analysis.
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