SEPIC AC-DC converter for aircraft application

This paper presents an AC-DC converter design for applications where mains frequency is widely varied and low input current harmonics and output voltage regulation are required, for example, in aircraft power systems. The proposed design employs a Single Ended Primary Inductance Converter (SEPIC) at the DC-end of a single-phase bridge diode rectifier. In discontinuous conduction mode (DCM), the SEPIC converter is a good alternative to the conventional buck or boost converter, where a low input current harmonic content is achieved with proper inductor selection of the converter. Here, a 28V, 1kW converter design with variable mains frequency (360 to 800Hz) is presented. The system performance was examined through a Matlab/Simulink model during both transient and steady state conditions.