U.S. Particle Accelerator School
U.S. Particle Accelerator School
Education in Beam Physics and Accelerator Technology

Accelerator Power Electronics Engineering


Texas A&M University Public Partnership & Outreach

Course Name:

Accelerator Power Electronics Engineering


James Sebek, SLAC National Accelerator Lab; Paul Bellomo, Retired SLAC National Accelerator Lab

Purpose and Audience
This course is an introduction to the field of accelerator power electronics and is suitable for advanced undergraduate and graduate students. The course is also appropriate for engineers and technicians working on power electronics as well as others in accelerator-related fields who wish to learn about the electrical systems powering accelerator magnets, kickers, klystrons, etc.

The student is required to have a good working knowledge of basic electronics, at the level of material in the textbooks: Electronics Fundamentals: Circuits, Devices and Applications by Thomas L. Floyd and David L. Buchla or Foundations of Analog and Digital Electronic Circuits by Anant Agarwal and Jeffrey Lang. The latter is the text for Anant Agarwal. 6.002 Circuits and Electronics. Spring 2007. Massachusetts Institute of Technology: MIT OpenCourseWare, https://ocw.mit.edu. License: Creative Commons BY-NC-SA.  The course notes and lectures are available through MIT OpenCourseWare at https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/index.htm. The student is also required to have the knowledge obtained in undergraduate level courses in: calculus, linear algebra, and be able to work with and understand first- and second-order ordinary linear differential equations associated with circuit theory.  It is recommended that the student have a working knowledge of computer aided circuit design tools.  We will use the LTspice simulation software from Analog Devices and will cover an introduction to LTspice that will be sufficient to complete the assignments.)

As with all USPAS courses, because of the short time in which the course is taught, the course material is presented in a compressed manner and the homework problems typically take a significant amount of time and effort each day.  Students seeking credit should not underestimate this effort.

It is the responsibility of the student to ensure that they meet the course prerequisites or have equivalent experience.

This course will focus on the fundamental principles of power electronics circuits and systems used in particle accelerators.  In daily lectures, the instructors will give theoretical presentations of various power electronics systems, followed up with practical examples of systems in use in accelerators.  Homework and computer laboratory assignments will reinforce these concepts.  The course aims to emphasize the intuitive concepts of the systems, using mathematical derivations only when needed to prove concepts or clarify this intuition.

Instructional Method
This course includes a series of daily lectures. Laboratory sessions will use LTspice simulations of power conversion circuits previously covered in class.  Students will be required to write and submit a report for the laboratory sessions.  The instructors will assign homework problems, based on the lectures, for completion outside of scheduled class time.  The instructors will also be available for discussion and questions outside of the scheduled class time.  Homework problems will be graded in a timely fashion to provide feedback.

Course Content
The course covers the types of power electronics equipment typically used in accelerators to power coils of magnets for beam steering and focusing as well as the power sources used to provide power to RF generators that power sources for beam generation, acceleration, steering, and focusing.  The course will emphasize the specification of complete power systems for the proper operation of, and matching to, magnet, capacitor, and klystron loads.  The first part of the course will discuss the AC power concepts important to provide the raw power to the electronics.  These concepts include input line voltage, single line diagrams, power factor, harmonic distortion, etc.  The largest fraction of the course is devoted to power electronic circuits for “warm” and superconducting DC magnet applications.  This section will cover standard DC power supply design topologies.  In this section we will also discuss the selection of appropriate power elements for the various applications, concepts of transformer design, high performance feedback systems, and interfaces to the accelerator control system.  In another course section we will present an introduction to pulsed power applications for loads such as septum magnets, kicker magnets, and klystrons.  This section will include transmission line theory, impedance matching, classical pulse forming networks, and newer solid-state topologies. (Students interested in learning more about pulsed power systems should also consider enrolling in the Pulsed Power Engineering course https://uspas.fnal.gov/programs/2022/onlinetamu/courses/pulsed-power.shtml given in the second half of the school.) In another course section, we will focus on specifying, improving, and maintaining the reliability of power electronics required for modern accelerators.  Finally, we will address safety issues working around high voltage, high power systems, including personnel safety, machine protection, and code compliance

Reading Requirements
Extensive class notes will be provided that will serve as the primary reference.  These notes will be a revised version of those used in 2019:  https://uspas.fnal.gov/materials/19NewMexico/NewMexico-PowerElectronics.shtml

The course textbook, "Fundamentals of Power Electronics" by Robert W. Erickson and Dragan Maksimovic, Springer, Third Edition, 2020, is a very complete text and reference on power electronics.  It covers much, but not all, of the material to be presented in this course.  The course text will be provided by the USPAS to the student before the start of classes.

Suggested additional power electronics references (neither mandatory nor provided by USPAS) are:
“Power Electronics” by Daniel W. Hart, Valparaiso University, McGraw-Hill, 1st edition, 2011
"Elements of Power Electronics" by Philip T. Krein, University of Illinois, Oxford University Press, Second Edition, 2014
"Principles of Power Electronics", by John G. Kassakian, Martin F. Schlecht and George C. Verghese, MIT, Addison-Wesley, 1991
"Power Electronics: Converters, Applications, and Design" by Ned Mohan, Tore M. Undeland, and William P. Robbins, University of Minnesota, John Wiley, Third Edition, 2002.

Credit Requirements
The basis for student evaluations are: performance on homework assignments (60% of final grade), classroom participation (20% of final grade), and a computer/lab session (20% of final grade).

Indiana University course number: Physics 671, "Advanced Topics in Accelerator Physics"
Michigan State University course number: PHY 963, "U.S. Particle Accelerator School"
MIT course number: 8.790, "Accelerator Physics"