14207

1297 دكتري

دكتري

مهندسي برق

اصفهان : دانشگاه صنعتي اصفهان

1397

دوازده، [۲۵۹]ص.: مصور، جدول، نمودار

حسين فرزانه فرد

احمدرضا تابش

رسول دهقاني، حميدرضا كارشناس

1397/10/10

كتابنامه

برق و كامپيوتر

مهندسي برق و كامپيوتر

ID1297 دكتري

7 4 مبدل در هم تنیده بسیار افزاینده کلیدزنی نرم خازن سری با کلید 622 7 5 نتیجه گیری 822 فصل هشتم نتیجه گیری و پیشنهادها 922 8 1 نتیجه گیری 922 8 2 پیشنهادها 332 مراجع 632 چکیده مبسوط به زبان انگلیسی 942 دوازده

Improving Efficiency and Reducing Number of Elements in the Interleaved Step Up High Step Up Converters Baharak Akhlaghi baharak akhlaghi@ec iut ac ir 22 September 2018 Department of Electrical and Computer Engineering Isfahan University of Technology 84156 83111 Isfahan IranSupervisor Dr Hosein Farzanehfard hosein@cc iut ac irAdvisor Dr Ahmadreza Tabesh Department Graduate Program Coordinator Dr Gholamreza Yousefi Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan IranAbstractIn this dissertation the existing step up and high step up interleaved converters are investigated evaluated andtheir limitations are expressed In order to overcome the limitations of the existing interleaved soft switchingstep up and high step up converters four ZVT interleaved boost converters are proposed and the laboratoryprototypes are implemented The proposed ZVT cells are also applied to other types of interleaved convertersand thus four families of fully soft switched interleaved ZVT converters are proposed In the proposedconverters the switching losses of all the main and auxiliary switches and the reverse recovery problem of allthe diodes are eliminated In these converters using only one auxiliary switch along with low number ofauxiliary elements has led to simple structures with low conduction losses in comparison with the existingcounterpart converters In the proposed ZVT interleaved converters soft switching performance is achieved in awide range of load variations The proposed ZVT interleaved converters are compared to each other as well asto the existing prominent counterparts Subsequently in order to increase the voltage gain of the converters andreduce the voltage stress of the elements some soft switching high step up interleaved converters areintroduced The proposed fully soft switched interleaved high step up converters have a very low number ofelements and very high voltage gain in comparison with the existing counterparts These two interleaved highstep up converters employ passive lossless snubbers to provide soft switching condition in a broad range of loadvariations These converters are completely analyzed and the experimental waveforms of the laboratoryprototypes are presented Besides the interleaved high step up converters with passive lossless snubberspresented in this dissertation are compared with their existing counterpart converters and with each other In thisdissertation also a quasi resonant interleaved high step up converter is introduced and its simulation results arepresented This converter is capable of eliminating switching and capacitive turn on losses of the converterswitches and reverse recovery problem of the diodes Also an interleaved high step up converter with seriescapacitor is introduced which is capable of enhancing the converter voltage gain and providing soft switchingconditions The simulation waveforms of this converter are also presented Key WordsStep up high step up converters interleaved converters soft switching ZVT passive lossless snubbers quasi resonant converters IntroductionRecently renewable power resources utilizing advanced technologies are getting remarkableattention This is due to their extensive availability rapid growth of energy demand reduction of fossil energy resources and environmental issues like greenhouse gas emissions Nevertheless the low output voltage of renewable sources requires to be elevated by aninterface cell to the voltage level of DC bus For this purpose step up and high step upconverters are widely utilized Step up converters are the converters with voltage gain in theorder of a boost converter voltage gain while converters with higher voltage gain are calledhigh step up converters Typical boost and buck boost topologies as step up converters mustoperate at very high duty cycles D to provide high voltage gains This results in low width

حسين فرزانه فرد

احمدرضا تابش

رسول دهقاني، حميدرضا كارشناس