Burst FM Control of LLC Resonant Converter with Multiplier for High Efficiency and Low Ripple in TWT Power Supply. Issue 2 (21st October 2021) - Li, Jianbing
Abstract : The burst frequency modulation (FM) control mode is applied to an LLC resonant converter with multiplier in this study for enhanced efficiency and low voltage ripple at light load. This control mode provides an effective solution to high‐voltage power supply with wide‐range loads such as the traveling wave tube (TWT) power supply. Shortages in the LLC resonant converter with multiplier at light load are analyzed and a burst FM control strategy is proposed accordingly. The principle of the LLC resonant converter with multiplier under this control mode is then analyzed in detail. A ripple control strategy and zero voltage switching (ZVS) method are proposed, where the controller is implemented by digital signal processing (DSP). The prototype of a TWT power supply based on the burst FM control mode is completed accordingly. In the burst FM control mode applied in this study, ZVS is realized from light load to full load, and the efficiency at light load is improved by 7% comparing with conventional FM mode. The voltage ripple at light load is reduced by 5 V comparing with conventional burst mode. The experimental result indicates that the proposed method is feasible and effective. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.