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dc.contributor.authorWan, Hongmeien_US
dc.date.accessioned2014-03-14T20:35:34Z
dc.date.available2014-03-14T20:35:34Z
dc.date.issued2012-04-30en_US
dc.identifier.otheretd-05072012-141855en_US
dc.identifier.urihttp://hdl.handle.net/10919/32343
dc.description.abstractThe battery charger plays an important role in the development of electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs).This thesis focuses on the DC-DC converter for high voltage battery charger and is divided into four chapters. The background related to EV battery charger is introduced, and the topologies of isolated DC-DC converter possibly applied in battery charge are sketched in Chapter 1. Since the EV battery charger is high voltage high power, the phase-shifted full bridge and LLC converters, which are popularly used in high power applications, are discussed in detail in Chapter 2. They are generally considered as high efficiency, high power density and high reliability, but their prominent features are also limited in certain range of operation. To make full use of the advantages and to avoid the limitation of the phase-shifted full bridge and LLC converters, a novel hybrid resonant and PWM converter combining resonant LLC half-bridge and phase shifted full-bridge topology is proposed and is described in Chapter 3. The converter achieves high efficiency and true soft switching for the entire operation range, which is very important for high voltage EV battery charger application. A 3.4 kW hardware prototype has been designed, implemented and tested to verify that the proposed hybrid converter truly avoids the disadvantages of LLC and phase-shifted full bridge converters while maintaining their advantages. In this proposed hybrid converter, the utilization efficiency of the auxiliary transformer is not that ideal. When the duty cycle is large, LLC converter charges one of the capacitors but the energy stored in the capacitor has no chance to be transferred to the output, resulting in the low utilization efficiency of the auxiliary transformer. To utilize the auxiliary transformer fully while keeping all the prominent features of the previous hybrid converter in Chapter 3, an improved hybrid resonant and PWM converter is proposed in Chapter 4. The idea has been verified with simulations. The last chapter is the conclusion which summaries the key features and findings of the two proposed hybrid converters.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartWan_HM_T_2012.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectLLC Resonant Converteren_US
dc.subjectHybrid Resonant and PWM Converteren_US
dc.subjectPhase-shifted Full Bridge Converteren_US
dc.subjectDC-DC Converteren_US
dc.subjectElectric Vehicle Battery Chargeren_US
dc.titleHigh Efficiency DC-DC Converter for EV Battery Charger Using Hybrid Resonant and PWM Techniqueen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical and Computer Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineElectrical and Computer Engineeringen_US
dc.contributor.committeechairLai, Jih-Sheng Jasonen_US
dc.contributor.committeememberMeehan, Kathleenen_US
dc.contributor.committeememberNelson, Douglas J.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05072012-141855/en_US
dc.date.sdate2012-05-07en_US
dc.date.rdate2012-09-11
dc.date.adate2012-09-11en_US


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