Phase-Shifted Quad-Input LLC Converter with Variable Pulse Width Modulation1

In this paper, a novel quad input DC-DC converter is proposed for photovoltaic (PV) applications where four PV panels are connected to the load through a single LLC tank. This topology uses Frequency Switching Modulation (FSM) to regulate the load and Phase Shift Modulation (PSM) to balance the power between both sides of the converter. In addition, variable duty cycle Pulse Width Modulation (PWM) on each side to control the power supplied by the panels within it. This means four degrees of freedom are used to control all the ports of the proposed converter. This topology features a low-cost solution due to the number of components reduction and centralized control which leads to easier functionality and higher efficiency. This paper includes the detailed topology analysis, steady-state operation, and the gain equations are derived. Finally, the theoretical analysis is verified by simulation using MATLAB Simulink platform.