Fundamentals of three-phase induction motors, variable frequency drives

This session is designed for technicians and engineers who want to understand the fundamental design, construction and operation of three phase induction motors and variable frequency drives (VFDs). Separate learning objectives follow for each section, though one quiz covers both topics.

By Control Engineering September 27, 2023
Courtesy: CFE Media and Technology

Learning objectives:

  • Learn how a three-phase induction motor is constructed.
  • Understand how a three-phase induction motor works by understanding the theories of Induction and Electromagnetism.
  • Examine important differences between a NEMA Design A and a NEMA Design B speed torque curve.
  • Learn differences of motor enclosures and the benefits of each.

Variable frequency drives (VFDs):

  • Examine the industrial and commercial applications for variable-frequency drives can be found.
  • Compare alternative motor starting methods to a variable frequency drive.
  • See the benefits of using a variable frequency drive and the purpose of components inside.


Daniel Schubert, ME University of Missouri – Science & Technology, Product Training Engineer – Drives

Dan started his engineering career with Yaskawa America in 2012. After a short stint as a drive repair engineer, he moved into Technical Training Services (TTS) and accepted the position as a Product Training Engineer with a focus on variable frequency drives. During his time in TTS, Dan has become the resident expert on fundamental motor and drive basics and was the primary driver behind the video you are about to watch. When not at work, you can find Dan working under the hood of a classic Chevy or making parts on his 3D printer.