Phase-shift-modulation for a current-fed isolated DC-DC converter in more electric aircraft

A Phase-Shift-Modulation (PSM) technique is proposed for an Active-Bridge-Active-Clamp (ABAC) topology. This topology is aimed for high power more-electric-aircraft applications. The proposed PSM has a complete switching harmonics cancellation on the low voltage terminal, independently of the operating conditions by effectively interleaving inductor currents. This results in a DC current at the low voltage terminal without any AC components, thus minimizing the passive filtering requirements. Additionally, when terminal voltages vary from their nominal values, the maximum power transfer capability of the ABAC converter can be greatly improved by using the proposed PSM. In this paper, the limitations of the conventional modulation technique for the ABAC converter are introduced and analysed. Then, a PSM scheme is proposed, which can provide high quality power on the low voltage terminal whilst maintaining high power transfer capability and efficiency in a wide operating range. The theoretical claims are validated by both simulation and experimental results on a 10kW 270V/28V ABAC converter