Comparison of prospective topologies for aircraft autotransformer-rectifier units

This paper explores the feasibility of employing 18-pulse autotransformer rectifier units (ATRUs) for more electric aircrafts, thus expanding the usage of these converters onto variable, high frequency applications. Particularly, the paper presents a detailed comparison of three 18-pulse ATRUs, based on input ac harmonic current distortion, output voltage regulation, common mode voltage, impact of impedance mismatch between rectifier paths and impact of input voltage harmonic distortion. The comparison is carried out for the full range of the input line frequency from 400 to 800 Hz. Key analyses and results obtained with Saber simulations are presented for validation of the presented work.