Principles of AC Machine Design

Through a building-block teaching approach, you will develop a basic understanding of AC electric machine design. By learning the core concepts of electromagnetic laws for machine design, magnetic circuit calculations, loss mechanisms, analytical design techniques, and other essential topics, you will improve your skills, and ultimately, your work. Recent developments in AC electric machine design also will be covered in this course.

• Engineers involved in the design, specification, and integration of components and systems requiring an understanding of AC machine design.
• Electrical and mechanical design engineers seeking to enhance their expertise in AC machine design.
• System engineers, project engineers, program managers, and technical leaders aiming to improve their skills and knowledge in AC machine design.

Attendees should have a bachelor’s degree in engineering or a related science, or the equivalent amount of industrial experience.

This course is part of the Electrified Systems Certificate series. Course may be taken individually as well.

Introduction to AC Machine Design

• Induction, PM, synchronous and switched reluctance

Sizing Laws: the influence of size

Power Sizing Equations

• Electric and magnetic loading
• Shear stress

Winding Types

• Full pitch and fractional windings
• Fractional pitch windings
• Distributed and concentrated windings
• Fractional slot windings

Magnetic Circuits

• Permeance and reluctance
• Multiple circuit paths
• Magnetic circuits with airgaps

Electric and Magnetic Materials

• Permanent magnet types
• Copper and aluminum
• Steel types
• Skin depth

Main Flux Path Calculations Using Magnetic Circuits

• Main magnetic circuit of an induction machine
• Effective gap and Carter''s coefficient
• Effective length
• Reluctance calculations

Leakage Reactance Calculations

• Slot leakage inductance
• Zigzag and differential leakage inductance
• Skew and end turn leakage inductance

Calculation of Machine Losses

• Eddy current and hysteresis losses
• Friction, windage, and copper losses

Testing and Parameter Characterization

Thermal Analysis and Cooling Systems

• Conduction, convection, and radiation
• FEA, CFD, lumped-parameters equivalent-networks
• Fan ventilation, liquid cooling

Manufacturing Topics

• Laminations, cores, windings, frames, assemblies
• Material and manufacturing tolerances

Vibrations and Noise

• Electromagnetic forces; harmonic components
• Mechanism of transmission
• Mitigation measures

Machine Design Examples

"Back of the Envelope" Calculations to Automated Optimal Computer Design

Finite Element Analysis

• Fundamentals
• Examples

Special Topics—How to Design Machines for Self-Sensing

Ayman El-Refaie

Ayman M. EL-Refaie received the M.S. and Ph.D. degrees in electrical engineering from the University of Wisconsin– Madison in 2002 and 2005, respectively. Since 2005, he has been with the Electrical Machines and Drives Laboratory, General Electric Global Research Center, NY, USA as a Principal Engineer and Project Leader. He is the author of more than 50 journal, and 85 conference publications with several others pending. He holds 45 issued U.S. patents with several others pending. His research interests include electrical machines and drives. Since January 2017 he became the Thomas and Suzanne Werner Endowed Chair in Secure and Sustainable Energy at Marquette University. He is a Fellow of the IEEE

Thomas Jahns

Dr. Thomas M. Jahns received his bachelors, masters, and doctoral degrees from MIT, all in electrical engineering.

Dr. Jahns joined the faculty of the University of Wisconsin-Madison in 1998 in the Department of Electrical and Computer Engineering.  He served for 14 years as a Co-Director of the Wisconsin Electric Machines and Power Electronics Consortium (WEMPEC), a world-renowned university/industry consortium in the electrical power engineering field.  Since 2021, he is the Grainger Emeritus Professor of Power Electronics and Electrical Machines.

Prior to coming to UW-Madison, Dr. Jahns worked at GE Corporate Research and Development (now GE Global Research) in Niskayuna, NY, for 15 years, where he pursued new power electronics and motor drive technology in a variety of research and management positions. His current research interests at UW-Madison include integrated motor drives and electrified propulsion for both land vehicles and aircraft.

Dr. Jahns is a Fellow of IEEE.  He received the 2005 IEEE Nikola Tesla Technical Field Award “for pioneering contributions to the design and application of AC permanent magnet machines”.  Dr. Jahns is a Past President of the IEEE Power Electronics Society.  He was elected to the US National Academy of Engineering in 2015 and received the IEEE Medal in Power Engineering in 2022.

Darren Tremelling

Darren Tremelling, Ph.D. is currently a Principal Scientist in ABB Corporate Research.

After completing his doctorate in WEMPEC, University of Wisconsin - Madison, Dr. Tremelling has worked in ABB Corporate Research. His research experience covers a range of electric machines for various applications with power ratings between 1 [kW] to 7 [MW].

James Swanke

James Swanke is an electrical machine designer with an extensive academic and professional background in electrical engineering. Graduating from the University of Wisconsin-Madison with a B.S. in 2014, a M.S. in 2019, and a PhD in 2023, James has developed a deep expertise in high-performance electrical machines. Prior to pursuing advanced degrees, he gained valuable experience working for Siemens specializing in the electromagnetic design of induction machines. During graduate studies, his research focused on the advancement of high-power density and fault-tolerant electrical machines for aerospace propulsion applications. Currently, James applies this extensive knowledge at H3X Technologies, where he continues to work on the development of cutting-edge permanent magnet machines.