18-Pulse Autotransformer with Differential Delta Connection for MEA Application

This paper presents a study concerning the design and analysis of an 18-pulse delta differential autotransformer rectifier unit (ATRU) with low kVA rating for more electric aircraft (MEA) application. The proposed autotransformer is designed to operate with variable frequency power supplies (400-800Hz) and allows considerably reduction of kilovoltampere (kVA) rating in the range of 0.15 p.u., as well as high-power factor and reduced harmonic distortion of the input line current (THDi). Simulation and experimental results are presented corroborating the exposed theory, especially with regard to meeting the limits imposed by the DO-160 standard.