Hybrid Modulation of Parallel-Series LLC Resonant Converter and Phase-Shift Full Bridge Converter for A Dual Output DC-DC Converter

Abstract-A novel pulse frequency and phase shift hybrid modulated dual output DC-DC converter is proposed in this paper. The proposed converter is composed of hybrid modulation of an input-parallel-output-series LLC resonant converter and a phase-shift full bridge converter. The output voltage of the LLC resonant converter is regulated by the switching frequency, while the output voltage of the phase-shift full bridge converter is regulated by the phase angle; therefore, the two output voltages are regulated independently and free from cross regulation. The series inductor of the phase-shift full bridge converter does not need to be specially designed to help achieving the soft switching operation, and the duty cycle loss could be mitigated. Zero-voltage switching can be achieved on the power switches in the whole load range. Finally, a 1.2kW 400-input 200V-400V and 48V output prototype is built and tested to verify the effectiveness of the proposed converter.