Project and Performance Evaluation on an Optimized 18-Pulse Rectifier With Delta-Differential Connection ATRU and Cascaded Boost Converters for More Electric Aircraft

This paper presents the design and analysis of a special Rectifier Unit (RU) composed of a Delta-Differential Symmetric 18-pulse Autotransformer and cascade Boost converters for applications in More Electric Aircraft (MEA), which is denominated as RU-DDS18PATR+Boost. The cascaded Boost converters provide dc-link regulation, while eliminating the need to use interphase transformers (IPTs), interphase rectors (IPRs), and zero-sequence blocking transformers (ZSBTs), thus contributing toward decreasing the complexity and at the same time increasing reliability. The proposed RU-DDS18PATR+Boost operates with an active current shaping strategy in order to meet the harmonic content restrictions imposed by the DO-160F standard, while allowing for the design of a DDS18PATR with a notable kVA rating of 21.03%. The performance of the RU-DDS18PATR+Boost was analyzed operating in a system with a supply voltage of 115VAC and variable frequency in the range of 360Hz to 800Hz, which is converted to 540VDC. Experimental results are presented corroborating the theory put forward herein, especially with regard to meeting the limits imposed by the DO-160F standard.