PWM Dc-to-Dc Power Conversion Chapter 1 PWM Dc-to-Dc Power Conversion Pulsewidth Modulated Dc-to-DC Power Conversion

Head Lamp Drive Circuit in Automobile Energy Source and Load - Source: - Load: Conventional Resistive Solution - Control low: - Ohmic loss at: Dc-to-Dc Power Conversion

Problem of Resistive Solution Assumptions: - Ploss : - Efficiency : Consequence of poor efficiency Dc-to-Dc Power Conversion

Dc-to-Dc Power Conversion as Alternative Solution Control law: No power loss in circuit:

Dc-to-Dc Power Conversion Power conversion: Changing electrical energy/power from one form to another form using electronics devices Examples: Power electronics: Electronic engineering that deals with all types of power conversions while questing the Dc-to-Dc power conversion: Process of changing the voltage level of a dc source to another value Dc-to-Dc Power Conversion

Classification of Power Conversion Dc-to-Dc Power Conversion

Dc-to-Dc Power Conversion System Dc source with non-ideal characteristics - Standalone dc source: - Rectified ac source: Dc-to-Dc Power Conversion Load as dynamic current sink with non-resistive impedance - Electric equipment: non-resistive load impedance

Dc-to-Dc Power Conversion System Dc-to-dc converter as voltage source Function of dc-to-dc converter: Elements of dc-to-dc converter - Power stage: semiconductor switch - Controller: processors, ICs, and discrete components Dc-to-Dc Power Conversion

Features and Issues of PWM Dc-to-Dc Converter Power stage components - Semiconductors: high frequency switching - Inductors and capacitors: periodic voltage/current excitation - Transformers: periodic voltage/current excitation Power stage configurations - Accommodation of input voltage and load current requirements - Very large or very small voltage conversion ratio - Galvanic isolation between source and load Dynamic modeling and analysis - Closed-loop feedback control: stability - Dynamic modeling to accommodate conventional analysis technique Dynamic performance and controller design - Static and dynamic performance - Dynamic performance: stability, transfer functions, transient responses - Feedback controller design for optimal dynamic performance Dc-to-Dc Power Conversion

POWER ELECTRONICS: 2012 Fall ● General Information Office: IT3-314 Office Hour: Fri 9:00-12:00 AM Phone: 950-6603, Home Page: http://m80.knu.ac.kr/~SMPC/ ● Course Objective: As an introductory course in power electronics, the class will address basic principles, analysis techniques, and applications of modern power electronics with a strong emphasis on switchmode dc-to-dc power conversions. The students would learn methods of solving various power electronics problems using their knowledge about electronics, circuit theories, and control theories. ● Text: Byungcho Choi, “Fundamentals of Switchmode Dc-to-Dc Power Conversions. 2nd Edition, 2010, Young Publishing http://www.bandinlunis.com/front/product/detailProduct.do?prodId=3196848   Reference: R.W. Erickson, “Fundamentals of Power Electronics,” 1997. D. W. Hart, “Introduction to Power Electronics,” 1997, Prentice-Hall P. T. Krein, “Elements of Power Electronics,” 1998, Oxford  

Tentative Course Outline Topic Major Contents Week Chapter 1: Basics of Power Electronics  Introduction to power electronics  Semiconductor switches and switching circuits  Energy storage/transfer devices and switching circuits 3 weeks Chapter 2: Step-down Dc-to-Dc Power Conversion Circuit: Buck Converter  Basic principles of buck converter  Time-domain analysis of buck converter  Discontinuous-conduction mode of operation  Closed-loop control of buck converter 3 week Chapter 3: Dc-to-Dc Power Converter Circuits  Step-up dc-to-dc converter  Buck/boost converter 1 week Midterm Test  Flyback converters  Bridge-type converters  Forward converters 2 weeks Chapters 4, 5, and 6: Modeling, Control Design and Analysis of PWM Converters  Average modeling of PWM converters  Small-signal modeling of PWM converters  Small-signal analysis of PWM dc-to-dc converters  Compensation design and closed-loop analysis 4 weeks Final Exam  Grading Policy: Midterm Test: 42%, Final Exam: 42%, Homework: 16%  Honor System: Students should develop their own solutions to homework problems. Late homework will not be accepted with no exceptions.