Show simple item record

dc.contributor.authorWang, Qiongen
dc.date.accessioned2017-06-13T19:44:19Zen
dc.date.available2017-06-13T19:44:19Zen
dc.date.issued2015-05-12en
dc.identifier.otheretd-07072015-210108en
dc.identifier.urihttp://hdl.handle.net/10919/78147en
dc.description.abstractThe More-electric aircraft (MEA) concept has been raised since 1990s in order to increase fuel economy and reduce environmental impact of aircrafts. The fundamental of the concept is to replace pneumatic, hydraulic and mechanical systems in conventional aircrafts with its electrical equivalent that is lighter and more reliable. In this movement, power electronics technology plays a key role in interfacing the new types of electrical loads to the new aircraft electrical power system. One of the major tasks for power electronics circuits in MEA is to transfer aircraft variable frequency AC voltage into DC voltage, which could be conveniently utilized by different types of loads or power buses. The converters carrying out the task is commonly known as "rectifiers". This work aims at designing and constructing rectifiers that can work efficiently and reliably in more-electric aircrafts. One of the major challenge for these rectifiers comes from the complex aircraft environment. The ambient temperature could be as high as 70 ºC. Moreover, active cooling for converters may not be desirable. To deal with this, rectifiers should achieve extreme efficiency (especially at full load) so that all the components are not overheated without active cooling. This work aims at achieving extreme converter efficiency through advanced converter topologies and design. Both single-phase and three-phase rectifiers are discussed in this work. For single-phase rectifiers, this work focused on boost-type power factor correction (PFC) converters due to the promising efficiency and good PFC characteristics. The well-known two-level semi-bridgeless PFC boost rectifier, together with its interleaved and three-level counterparts, are studied and compared in this work. The operation principles of the converters are analyzed. Models and methods for converter efficiency evaluation are discussed. The efficiency evaluation of the topologies shows the advantage of three-level topologies and interleaved topologies in achieving higher efficiency and better thermal management. For three-phase rectifiers, two-level boost rectifier, three-level neutral point clamped (NPC) rectifier and Vienna rectifier are investigated. The evaluation shows the advantage of Vienna rectifier in achieving high efficiency due to reduced switching loss. Based on the evaluation of single-phase and three-phase active rectifiers, the author selected interleaved Vienna rectifier to achieve extreme efficiency and avoid overheating problem. The operation principle of the interleaved Vienna rectifier is introduced, with particular attention paid to the circulating current generated by interleaving operation. The design procedure for achieving maximum efficiency is described. Finally, a prototype of the proposed converter is constructed, which achieves 99.26% efficiency at nominal load.en
dc.language.isoen_USen
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectHigh efficiencyen
dc.subjectmore-electric aircraftsen
dc.subjectPFC converteren
dc.subjectinterleaved converteren
dc.subjectVienna converteren
dc.titleDesign of Extreme Efficiency Active Rectifier for More-electric Aircraftsen
dc.typeThesisen
dc.contributor.departmentElectrical and Computer Engineeringen
dc.description.degreeMaster of Scienceen
thesis.degree.nameMaster of Scienceen
thesis.degree.levelmastersen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.disciplineElectrical and Computer Engineeringen
dc.contributor.committeechairBurgos, Rolandoen
dc.contributor.committeememberBoroyevich, Dushanen
dc.contributor.committeememberLi, Qiangen
dc.type.dcmitypeTexten
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07072015-210108/en
dc.date.sdate2015-07-07en
dc.date.rdate2015-07-30en
dc.date.adate2015-07-30en


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record