Analysis and Design of Interleaved DCM Buck–Boost Derived Three-Phase PFC Converter for MEA

Abstract

In more-electric aircraft (MEA), the synchronous generators are connected directly to the turbo engine to develop a constant-voltage variable-frequency (CVVF) ac supply bus. In addition, the MEA has adopted a high-voltage dc bus in its power system to cater to the various categories of load used by aircraft. Therefore, this change in power paradigm has created a requirement for ac-dc power factor correction (PFC) converters to convert CVVF ac to constant dc with high power quality in a reliable manner. In this article, a three-phase interleaved buck-boost-derived PFC converter is operated in discontinuous current conduction mode to realize the inherent unity power factor (UPF) operation for MEA wide range of supply frequency. The benefits of the proposed converter are higher power density, efficiency, and reliability. The advantages of the proposed converter are demonstrated by performing an analytical comparison with the single-cell three-phase buck-boost derived PFC converter and presented the relevant results. The experimental results from a 2.0-kW laboratory concept-proof hardware prototype have been provided to confirm the proposed converter UPF operation for a wide range of supply frequencies. A low input power factor of 0.9996 and a minimum current THD of 2.52% are recorded from the developed prototype.