4477

4205

كارشناسي ارشد

الكترونيك

اصفهان: دانشگاه صنعتي اصفهان، دانشكده برق و كامپيوتر

1387

نه، 112، [II]ص: جدول، نمودار

ص.ع.به:فارسي و انگليسي

حسين فرزانه فرد

محمد مدني

88/2/29

1396/09/12

كتابنامه

مهندسي برق و كامپيوتر

ID4205

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

Soft Switching Three Phase PWM Inverter with Quasi Parallel Resonant DC Link Mohammad Reza Amini mrezaaminy@ec iut ac ir Date of Submission 3 14 2009 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Hosein Farzanehfard hosein@cc iut ac irAbstractNowadays inverters have found many applications in industry such as induction motorsdrives with speed control uninterruptible power supplies AC power supplies with voltageand frequency control capability and active power filters In order to reduce the size ofoutput filter increase the current or voltage quality and to eliminate audio noise in circuitmagnetic elements high switching frequency is indispensable However switching lossesincrease at higher switching frequencies In order to reduce switching losses and switchesvoltage and current stresses usually turn on and turn off snubbers are employed whichincrease total inverter losses Typical method employed to reduce switching losses and stresses is applying softswitching techniques In these techniques extra elements are added to circuit thatapproximately eliminate overlap of voltage and current at turn off and turn on instants These inverters are divided in to load resonant inverters and DC link resonant inverters Load resonant inverters have high number of auxiliary switches and are used in high powerapplications In medium power applications usually DC link resonant inverters are used In these inverters only one resonant circuit exists in their DC link In recent years theresearch is mainly concentrated on increasing the efficiency and decreasing the number ofextra elements in inverters There are usually two auxiliary switches or more in the inverterDC link auxiliary circuit In current thesis reducing extra elements particularly auxiliary switches is achieved byemploying new topologies To achieve this goal three novel quasi resonant DC linkinverters are suggested and the converter operation and theoretical waveforms arepresented Also design consideration of each converter is provided To validate thetheoretical analysis two prototype converters are implemented and the results arecompared with theoretical analysis Keywords 1 Three phase inverter 2 Soft switching 3 Quasi parallel resonant DC link 4 Pulsewidth modulation 5 Zero voltage switching 6 Zero current switching

حسين فرزانه فرد

محمد مدني