DESIGN AND ANALYSIS OF TWO STAGE BRIDGELESS BOOST PFC FED FULL BRIDGE LLC RESONANT CONVERTER FOR CHARGING APPLICATION

Abstract

In the proposed system, the Bridgeless Boost PFC converter is utilized as the front end AC-DC conversion stage to improve input power quality and reduce conduction losses associated with conventional bridge rectifier based topologies. The elimination of the diode bridge from the main conduction path contributes to improved efficiency and better thermal performance while maintaining an improved input power factor. The PFC stage is designed to generate a regulated intermediate DC bus voltage of approximately 400 V. The second stage employs a Full Bridge LLC Resonant Converter for isolated DC-DC conversion and output voltage regulation. The LLC resonant topology is selected due to its ability to achieve soft switching operation, particularly Zero Voltage Switching (ZVS), which helps reduce switching losses and improve overall conversion efficiency. The converter is designed to regulate the output voltage suitable for 48 V battery charging applications. The complete charging system is modeled and simulated using MATLAB Simulink to analyze the operational performance of both converter stages. The simulation results demonstrate improved input power quality, regulated DC bus voltage, stable output voltage performance, and effective integration of both converter stages for battery charging applications. The proposed converter configuration offers an efficient and reliable solution for medium power battery charging systems, making it suitable for future applications requiring improved energy efficiency and enhanced power quality.