Phase-Shifted Full-Bridge Converter for a Half-Current-Multiplier Rectifier Using an Autotransformer-Based Filter

Abstract

A half-current-multiplier rectifier (HCMR) is proposed, which is capable of increasing the output filter current of phase-shifted full-bridge (PS-FB) by 1.5 times. The HCMR filter is based on an autotransformer structure and improves the valid duty cycle of the PS-FB converter by using the induced current from the common winding. The primary current will decrease rapidly during the dead time period, effectively reducing the transition current level and the transition period. Accordingly, the new valid duty period is almost close to the terminal v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AR</sub> period, over the entire load range, and the power delivery goes nearly in the entire v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">AR</sub> period. Experiments have shown that although the zero-voltage switching (ZVS) of all switches can usually implement in continuous-conduction mode (CCM) and most discontinuous-conduction modes (DCMs), it still performs excellently at light loads. Maintenance of 89%-94% high efficiency over a wide load range is like the performance of current-doubler rectifier (CDR) filter.