The Physics of AC Machines

  1. John Chiasson

Published Online: 27 JAN 2005

DOI: 10.1002/0471722359.ch5

Modeling and High-Performance Control of Electric Machines

Modeling and High-Performance Control of Electric Machines

How to Cite

Chiasson, J. (2005) The Physics of AC Machines, in Modeling and High-Performance Control of Electric Machines, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/0471722359.ch5

Publication History

  1. Published Online: 27 JAN 2005
  2. Published Print: 18 MAR 2005

ISBN Information

Print ISBN: 9780471684497

Online ISBN: 9780471722359

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Keywords:

  • induced EMFs in the rotor loops;
  • magnetic forces and torques on the rotor loops;
  • slip speed;
  • microscopic viewpoint

Summary

This chapter explains the fundamental physics behind the working of induction and synchronous machines. Specifically, this chapter uses a simplified model of the induction motor and shows how voltages and currents are induced in the rotor loops by the rotating magnetic field established by the stator currents. Then it is shown how torque is produced on these induced currents by the same stator rotating magnetic field that induced them introducing the idea of slip.

Similarly, the synchronous motor is analyzed to show how the rotating radial magnetic field established by the stator currents produces torque on a rotor carrying constant current.

An optional section on the microscopic point of view of the physics of the induction motor is also presented. This includes a discussion of how the electric and magnetic fields change as one goes between coordinate systems that are rotating with respect to each other and how one reinterprets the physics of the machine's operation.

The chapter ends with another optional section of the steady-state behavior of an induction machine with a squirrel cage rotor.