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Engineering Online

ECE 592 620 Resonant Power Converters

3 Credit Hours

Resonant Power Converters course covers the analysis, modeling, design, and control of high-frequency resonant power rectifiers, inverters, and DC-DC converters. More specific topics are:
• A general overview of the advantages, concepts, and challenges in designing and operating high-frequency resonant converters. Some of the topics include the converters’ classification (half-wave, voltage or current driven, series- or parallel-loaded); survey, selection, and modeling of semiconductor switches for application in resonant converters; loss mechanisms and loss calculation; hard- and soft-switching concepts; zero-voltage and zero-current switching (ZVS and ZCS) notions; modeling of nonideal and nonlinear reactive elements; figures of merit for resonant converters comparison (switch stress, output-power capability), etc.
• Modeling, analysis, and design of Class D and Class E voltage- and current-driven resonant rectifiers. Three types of rectifiers will be studied: the half-wave, bridge, and transformer center-tapped rectifiers. A detailed analysis of the voltage- and current-driven Class D rectifiers and a current-driven Class-E rectifier will be provided.
• Modeling, analysis, and design of Class D and Class E series- and parallel-loaded resonant inverters. Resonant inverters overview, Class D voltage source series resonant inverter, current-driven Class E ZVS resonant inverter, and phase-controlled voltage-and current-source inverters will be studied. An overview of the advanced inverter topologies will be provided, and a brief discussion about the matching circuits will be presented.
• Resonant Power Converters consisting of a cascaded connection of a resonant inverter and a rectifier will be studied. The operation principles will be discussed, and design procedures will be outlined for a selected combination of compatible inverters and rectifiers. A detailed design procedure of the LLC converter will be presented. The principle of operation of quasi-resonant DC-DC converters will be illustrated with an example of a Buck ZVS quasi-resonant converter.
• Resonant converters modeling and control. The Extended Describing Function (EDF) modeling methods of resonant converters will be introduced and discussed in detail. Phase-controlled resonant converters will be introduced and used to illustrate the phase-control concept. Frequency control will be explained and illustrated in the example of an LLC converter.

Prerequisites

ECE 534 or equivalent.

Course objectives

At the end of this course, students should be able to:

  • Understand the operation of power rectifiers, resonant inverters, and resonant DC-DC converters. Classify different types of resonant converters and explain their applications.
  • Provide steady-state models of the most common resonant converters and derive analytical expressions that describe the relation between circuit components, the input power source, the output load, and the operating frequency.
  • Identify and calculate the resonant converter losses.
  • Design practical resonant rectifiers, inverters, and converters adhering to typical application requirements and practical constraints.
  • Derive large- and small-signal models of a resonant power converter.
  • Design a phase-shift controller for a resonant power converter.
  • Design a frequency controller for a resonant power converter.
  • Use MATLAB, Simulink, and LTSpice to analyze and simulate resonant power converters.
  • Implement a controller in a microcontroller to regulate the voltage or current at the output of a resonant converter.

Course requirements

Component      Weight

Homework           40%

Project                  25%

Exam                    35%

Total                     100%

Course Topics

Topic 1: Introduction to Resonant Power Conversion: Course planning and the syllabus overview; Resonant Power Converters – classification and overview; Semiconductor switches for resonant converters – an overview; Hard-switching vs. ZVS and ZCS switching; Loss modeling in resonant converters; Understanding non-idealities and nonlinear phenomena in reactive elements and switches;

Topic 2: High-Frequency Rectifiers: Class D Current-Driven Rectifiers; Class D Voltage-Driven Rectifiers; Class E low dv/dt Rectifiers;

Topic 3: Resonant Power Inverters; Resonant Inverters – introduction; Class D Series Resonant Inverter; Class D Parallel Resonant Inverter – Review; Class E ZVS Resonant Inverter; Phase-controlled voltage- and current-source inverters

Topic 4: Resonant Power Converters: Class D Series Resonant Converter; LLC resonant converter; the principle of operation of quasi-resonant DC-DC converters (a Buck ZVS quasi-resonant converter).

Topic 5: Resonant Power Converters Modeling and Control: Resonant power converter modeling – modeling principles; Extended Describing Function (EDF) modeling of a resonant converter. Design and implementation of frequency and phase-shift controllers.

Course Outline

LECTURES

Lectures will be held Monday and Wednesday from 3:00-4:15 pm in the 02332 classroom (EB3 building). The lectures will be recorded and uploaded to Panopto. Students can find recorded lectures at the Panopto Channel URL or access them through Moodle. The Zoom link for office hour meetings will be provided in Moodle at the beginning of the semester. Periodically, some extra material will be uploaded to Moodle, including extra material recorded by the instructor or the TA, educational videos to support learning, IEEE articles for reading, etc.

HOMEWORK

Homework will be assigned regularly on the Moodle website. There will be 5 HW assignments – one HW per topic. It may contain analytical calculations, simulations, and coding. Homework solutions should be scanned and submitted as a single PDF document on Moodle by the deadline specified in the assignment. If HW requires some codes or models to be submitted, they should be submitted as separate documents. Depending on the HW complexity, students will have 7 to 14 days to finish their assignments. No extension will be provided on a general basis, but each student has an opportunity to submit one HW up to 3 days after the deadline.

COURSE PROJECT

In the project, the students will analyze, model, study, and design a resonant converter not studied in the class. The students will specify component operating ratings and select adequate off-the-shelf components. For the converter, the students will determine the condition(s) of soft-switching and develop and verify through simulations the loss model of the converter. Finally, the small-signal model of the converter will be developed and utilized to design and test a frequency or phase-shift controller through simulations. The students will submit their pdf reports and all developed simulation models. A project oral defense will be organized at the end of the course.

EXAM

One exam will be administered during the course. The exam will cover the material studied in Topics 1-5. The exam will be organized through the Delta Testing Center, which may take up to 3 hours. The exam will be an open-book, open-notes exam, while other sources will not be permitted. The textbook and lecture notes will be accessible online through Moodle and the Safe Exam Browser (SEB).

OFFICE HOURS

The instructor will conduct office hours M/W from 5:00 pm – 5:45 pm. The meeting will be held in person (office at FREEDM Systems Center) or via the Zoom Web platform. The TA will conduct office hours via the Zoom Web platform or in person on Tuesdays and Thursdays, and the time will be determined at the beginning of the semester. The Zoom link for both meetings will be provided through Moodle at the beginning of the semester.

Textbooks

Resonant Power Converters – Marian K. Kazimierczuk; Dariusz Czarkowski

Edition: Second Edition

ISBN: 1-118-58586-0

Web Link: https://catalog.lib.ncsu.edu/catalog/NCSU878354

This textbook is required.

Software Requirements

Access to MATLAB and SIMULINK software (student’s version is enough) – Available on NCSU ECE computers – This software tool is required. Access to LTspice simulation software, available for free download from the Analog Devices website: https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html# – This software tool is required.

Please review the minimum computer specifications recommended by NC State University and Engineering Online. You should ensure that you have moderate-speed access to the NCSU system. Simple remote usage instructions will be given near the start of the course.

Created: 11/28/2023