U.S. Particle Accelerator School
U.S. Particle Accelerator School
America's National School of Accelerator Science and Technology

Accelerator Power Electronics Engineering

Sponsoring University:

Michigan State University

Course Name:

Accelerator Power Electronics Engineering
This class is full.

Instructors:

James Sebek, SLAC National Accelerator Lab; Paul Bellomo, ret. SLAC National Accelerator Lab (remote); Yugang Tan, Oak Ridge National Lab
TA: Jared Walden, SNS Oak Ridge National 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.

Prerequisites
The student is required to have a good working knowledge of basic electronics, at the level of material in the textbooks: Foundations of Analog and Digital Electronic Circuits by Anant Agarwal and Jeffrey Lang or Electronics Fundamentals: Circuits, Devices and Applications by Thomas L. Floyd and David L. Buchla. The former 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 and linear algebra, and be able to understand and work with first-order and second-order ordinary linear differential equations associated with circuit theory. A working knowledge of computer-aided circuit design tools is useful, but not required. We will have a laboratory/homework session that will use the LTspice simulation software from Analog Devices to investigate some circuits. (As part of that session, we will cover an introduction to LTspice that will be sufficient to complete the assignment.)

As with all USPAS courses, the course material is presented in a compressed manner and the homework problems typically take a significant amount of time and effort each day. The class grade is largely determined by the performance on the homework problems and laboratory session. Students seeking credit should not underestimate the effort required to complete the assignments and achieve a satisfactory grade.

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

Objectives
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. The instructors will assign homework problems each day, based on the lectures. These assignments are to be completed outside of scheduled class time. The instructors will make themselves available for discussion and questions outside of the scheduled class time. One major homework assignment will be a laboratory session that 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 session. 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. Some of the equipment powers magnet coils that steer and focus particle beams. Other equipment provides power to RF generators that are used to generate and accelerate the beams. The course will emphasize the specification of complete power systems, including matching the systems to magnet, capacitor, and klystron loads. The first part of the course will discuss the AC power concepts important to match the conventional utility 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. (The course will include a very brief discussion of superconducting magnets.) This section will cover standard DC power supply design topologies used in accelerator applications. 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 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
USPAS will provide electronic copies of extensive class notes that will serve as the primary reference. These notes will be a revised version of those used in 2022 which are available at https://uspas.fnal.gov/materials/22onlineTAMU/Accelerator-Power-Electronics.shtml

(Class textbook to be provided by USPAS) Principles of Power Electronics, 2nd ed. by J. G. Kassakian, D. J. Perreault, G. C. Verghese, and M. F. Schlecht,. Cambridge: Cambridge University Press, 2023.

There are several excellent texts concerning power electronics. These texts are general references that are valuable to the practicing power electronics engineer. They cover a wide range of power electronics but are not specialized to accelerator applications. As such, they cover much, but not all, of the material to be presented in the course. These texts are not mandatory nor will the USPAS provide copies to students. Some of these texts are:

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

USPAS Computer Requirements
USPAS will provide no Computer Lab; all participants are required to bring their own portable computer to access online course notes and computer resources and run LTspice to complete the laboratory/homework exercise. This can be a laptop or a tablet with a sufficiently large screen and keyboard. 64-bit Windows and MacOS systems that are wifi capable and have a standard web browser and mouse are acceptable. (LTspice executables from Analog Devices are only available for 64-bit Windows and MacOS.) Please download the appropriate executable from the Analog Devices LTspice download site. and verify that you can install it on your laptop. You should have privileges for software installs. If you are unable to download LTspice because you do not have a Windows or MacOS, we will provide a virtual machine to you via Amazon Web Services cloud computing https://uspas.fnal.gov/AWS-cloud-computers.shtml

If you are unable to bring a suitable computer, please contact uspas@fnal.gov ASAP to request a laptop loan. Very limited IT support and spare loaner laptops will be available during the session.

Michigan State University course number:  PHY 905 Special Problems, Section 704 Accelerator Power Electronics Engineering
Indiana University course number: Physics 671, "Advanced Topics in Accelerator Physics"
MIT course number: 8.790, "Accelerator Physics"