Three-Phase Hybrid Rectifier for HVDC Distribution System in More Electric Aircrafts

Abstract

High voltage direct current (HVDC) transmission systems have become popular, mainly within the scope of the More Electric Aircraft (MEA), where converters with high power density and robustness are required. In this context, this article presents a proposal of a Rectifier Unit (RU) based on a Three-Phase Hybrid Rectifier for MEA, which is denominated as TPHR-HVDC-MEA. The architecture of this RU is based on a Diode Bridge Rectifier Unit (DBRU) and on a three-phase Boost converter associated with a LLC Series Resonant converter (Boost+LLCSR). The main benefits of the proposed hybrid architecture are in reduced system size and higher conversion efficiency, since the Boost+LLCSR process only 50% of the rated power. Therefore, the robustness and reliability can be increased due to the reduced thermal stresses to which the semiconductors are subjected. A 1.2kW prototype was built in laboratory to corroborate the obtained results showing high efficiency (97%), great dynamic response for frequency variations at the alternating current (AC) power supply (400Hz to 800Hz) and compliance with the DO-160F standard (DHTi of 3.9%) are achieved. 1 Index Terms-Digital signal processor (DSP), high voltage DC (HVDC), hybrid rectifiers, more electric aircraft (MEA), power factor correction.