Course Title: 
Special Electric Machines
Course Code: 
Year Taught: 
Undergraduate (UG)
School of Engineering

'Special Electric Machines' is a course offered in B. Tech. in Electrical and Electronics Engineering program at School of Engineering, Amrita Vishwa Vidyapeetham

Unit 1

Stepping Motors

Introduction to all kinds of special machines, stepper motor, reluctance motors, hysteresis motors, brushless motors etc. Constructional features, Principle of operation, Variable reluctance motor, Hybrid motor, Single and multi-stack configurations, Torque equations, Modes of excitations, Characteristics, Drive circuits, Microprocessor control of stepping motors, Closed loop control.

Unit 2

Synchronous Reluctance Motors

Constructional features, Types, Axial and Radial flux motors, Operating principles, Variable Reluctance and Hybrid Motors, Voltage and Torque Equations, Phasor diagram, Characteristics.

Switched Reluctance Motors

Constructional features, Rotary and Linear SRMs, Principle of operation, Torque production, Steady state performance prediction, Analytical method, Power Converters and their controllers, Methods of Rotor position sensing, Sensor less operation, Closed loop control of SRM, Characteristics.

Unit 3

Permanent Magnet Synchronous Motors

Permanent Magnet materials, Magnetic Characteristics, Permeance coefficient, Recoil of a magnet, Principle of operation, Ideal PMSM, EMF and Torque equations, Armature reaction MMF.

Brushless D.C. Motors

Principle of Operation, Types, Magnetic circuit analysis, EMF and torque equations, Commutation, Power Controllers, Motor characteristics and control, Torque/speed characteristics,

  • S. A Nasar and I. Boldea, L. E. Unnewehr permanent magnet, “Reluctance and self–synchronous motors”, CRC Press inc.1993.
  • Miller, T. J. E. “Brushless permanent magnet and reluctance motor drives", Clarendon Press, Oxford, 1989.
  • T. J. E. Miller (Ed.), “Electronic Control of Switched Reluctance Motor”, Newman Power Engineering Series, 2001.
  • Paul Acamley, “Stepping Motor – A Guide to Theory and Practice”, IEE London. 2002.
  • B. K. Bose, “Modern power electronics and AC drives”, Prentice Hall of India, N J, 2002.