Vienna-Based Hybrid Three-Phase Step-Down PFC Rectifier for More Electric Aircraft

A 270 V high voltage dc (HVDC) architecture of more electric aircraft (MEA) mostly adopts two-stage power factor correction (PFC) converter due to the specific input-output relation, which is difficult to meet the demanding for high power density and low-voltage stress. In this article, a new hybrid three-phase (3ph) step-down PFC rectifier is proposed. It integrates a Vienna PFC converter with a diode-based switched capacitor converter (SCC) by capacitor multiplexing, which results in a low-voltage gain in a simpler structure without compromising the input power quality. Different from two-stage structure, the proposed topology can reduce the voltage stress by half in 3ph PFC system, which is more conducive to device selection. Furthermore, based on the integration of the proposed method, the neutral-point potential (NPP) self-balance on split capacitors of Vienna PFC converter is naturally achieved without any extra control strategy. Finally, a 1-kW experimental prototype with 98.1% efficiency of 115 ac/50-800 Hz to 270 Vdc is built to verify the analysis results.