ECEN5817, ECEE Department, University of Colorado at BoulderECEN 5817 Resonant and Soft-Switching Techniques in Power ElectronicsInstructor: Dragan Maksimovicoffice: ECOT 346phone: [email protected]: ECEN5797 Introduction to Power ElectronicsTextbook:Erickson and Maksimovic, Fundamentals of Power Electronics, second edition, Chapters 19 and 20Extensive supplementary notes and chapters on the course web siteECEN 58171Extensive supplementary notes and chapters on the course web siteECEN5817 website: http://ecee.colorado.edu/~ecen5817 Continuously updated through the semester, please plan to check frequentlyAtdlthdl•Announcements and lecture schedule• Lecture slides• Slides suitable for taking notes posted before the lecture• Annotated lecture slides posted after the lecture• Additional course materials• Homework assignments and solutionsECEN 58172• Password protected solutionsECEN5817, ECEE Department, University of Colorado at BoulderPreliminariesAssignments and exams• 10-12 week-long homework assignments posted on the course website• One midterm exam and one final exam, both take homePolicies (see details on the course website)• Collaboration on HW assignment is allowed • A blog has been setup to enable all students to exchange questions and comments on the course materials or homework problems; an invitation to contribute to the blog will be e-mailed this week• Copying someone else’s work is not allowed; all work you turn in must be your own• Absolutely no collaboration in any form allowed on the examsECEN 58173Grading• Homework (total) 40%• Midterm exam 20%• Final exam 40%Notes for off-campus students• Send an e-mail to the instructor at [email protected] to introduce yourself and provide your preferred e-mail address• Lectures posted on-line by CAETE within 24 hours, often within hours•Due dates are nominally the same as for on-campus students,one weekgrace period allowedDue dates are nominally the same as for oncampus students, one weekgrace period allowed• To submit your work, scan (b&w, 150 dpi is fine) into a single easily readable pdf• Include your name and e-mail address on the front page• Submit online via CU Boulder Desire2Learn (D2L) system• Alternative submission methods– Email the pdf as attachment to [email protected]– Fax to: 303-492-2758, addressed to Dragan Maksimovic, include ECEN5817, your name, hw#, and page number on every pageECEN 58174,,pg ypg– Mail to:Dragan MaksimovicECEE Department425 UCBUniversity of ColoradoBoulder, CO 80309-0425• Keep a copy of your workECEN5817, ECEE Department, University of Colorado at BoulderOffice hours, questionsWednesday, 11 am -12pm, Thursday 9-10:30am MTOffice: ECOT 346Telephone: 303-492-4863Telephone: 303-492-4863Blog or e-mail questions welcome at any time; will try to answer within 24 hours (M-F)Please use ECEN5817 in the subject line in any course-related emailsECEN 58175Introduction• Major power electronics applications: functionality, efficiency, size, cost• Power distribution systems, power supplies for wide range of applications• Energy-efficient lighting: electronic ballasts for fluorescent lamps, LED drivers• Hybrid and electric vehicles• Renewable energy systems: photovoltaic power systems, wind power systems• A simple converter example• Standard “hard-switching” operation• Resonant circuit basics• Switching losses• Soft-switching concept, introduction to zero-voltage switching (ZVS) converter operationECEN 58176• Introduction to resonant inverter operation• Advantages and disadvantages of resonant and soft-switching converters• Course outlineECEN5817, ECEE Department, University of Colorado at BoulderA Simple Converter Example• Synchronous buck point-of-load DC-DC converter• One leg of bridge DC-DC converters• One leg of single-phase or three-phase DC-AC invertersECEN 58177+LResonant Circuit Basics+–vinvout_RCECEN 58178ECEN5817, ECEE Department, University of Colorado at Boulder+–vin+vout_RCLResonant Circuit: Frequency ResponseECEN 58179+–vin+vout_RCLResonant Circuit: Time ResponseECEN 581710ECEN5817, ECEE Department, University of Colorado at BoulderkHz 521LCfoC5.0 kHz, 100DfsCircuit Example: Standard “Hard-Switched” PWM Operation6.1LCRQECEN 581711L = 100 H, C = 10 F, R = 5 standard hard-switched PWM operationECEN 581712ECEN5817, ECEE Department, University of Colorado at BoulderSwitching losses• Energy is lost during the semiconductor switching transitions, via several mechanisms:transitions, via several mechanisms:• Transistor switching times• Diode stored charge• Energy stored in device capacitances and parasitic inductancesSe i d t de i e ehtlldECEN 581713•Semiconductor devices are charge controlled–controlling charge must be inserted or removed to switch a deviceL = 100 H, C = 10 F, R = 5 : M1 turn-off, M2 turn on transitionECEN 581714ECEN5817, ECEE Department, University of Colorado at BoulderM1 turn-off, M2 turn-on transitionM1D1+–VDCDMVoutvsLiLECEN 581715D2M2Device capacitancesirfp4232 exampleECEN 581716ECEN5817, ECEE Department, University of Colorado at BoulderTransistor switching timesMOSFET• Majority carrier device• Turn-on and turn-off delays as well as current rise/fall times are in the order yof several tens of nanoseconds• At turn off, device output capacitance slows down vdsvoltage increase• No significant energy loss during MOSFET turn-off transition, even if current prior to turn-off is not zero; device capacitance is charged upIGBT• Conduction through built in bipolar transistor, a minority-carrier device; bh tb dttff (“ t t il” b d t tff)ECEN 581717base charge must be removed at turn-off (“current tail” observed at turn-off)• Turn-on/turn-off times in the hundreds of nanoseconds• If current prior to turn-off is not zero, energy loss during turn off can be significantTransistor switching speed and turn-off transition: IGBT exampleECEN 581718IRGP50B60 (IGBT+diode)ECEN5817, ECEE Department, University of Colorado at BoulderL = 100 H, C = 10 F, R = 5 : M2 turn off, M1 turn on transitionECEN 581719Hard-switched: M2 turn-off, M1 turn-on transitionM1D1+–VDCDMVoutvsLiLECEN 581720D2M2ECEN5817, ECEE Department, University of Colorado at BoulderDiode Stored Charge and Reverse RecoveryTypical test circuit and parameterECEN 581721and parameter definitions in diode data