Special Electromechanical Drives


In the end of this course, students should be able to:

 - Identify the main components of electromechanical drives, namely the power electronic converter, the electric machine, the command/control system and typical sensors.

- Apply fundamental concepts of electromagnetism and electromechanical energy conversion to the analysis of classic and special electric machines.

- Know distinct variables speed control techniques, with specific application to DC, synchronous and asynchronous motors.

- Understand and analyse transient regimes in electric machines, and its consequences in the operation of these devices.

- Understand and analyse special asynchronous machines, namely single-phase, linear three-phase, and polyphase  with variable poles, and their equivalent models.

- Understand superconducting materials, namely high temperature, and its application in electric machines.

- Select motors and remaining drives components.

General characterization





Responsible teacher

João Miguel Murta Pina


Weekly - 4

Total - Available soon

Teaching language



Theoretical electrotecnics

Electromechanical energy conversion


E. G. Janardanan, "Special Electrical Machines", PHI Learning, 2014.

In addition:

M. V. Deshpande, Electric Motors: Applications and Control, PHI Learning, 2010.
N. K. De, S. K. Dutta, Electric Machines and Electric Drives, Problems with Solutions, PHI Learning, 2012.
A. E. Fitzgerald, Charles Kingsley, Jr., Stephen D. Umans, Electric Machinery, 6th Ed., McGraw-Hill, 2003.
S. A. Nasar, Schaum’s outline of theory and problems of electric machines and electromechanics, McGraw-Hill, 1998.
T. Wildi, Electrical Machines, Drives, and Power Systems, 5th Ed., Prentice Hall, 2002.

Teaching method

Available soon

Evaluation method

Assessment comprises three tests during semestre, T1 to T3.

Final grade, Nf, is built by the following weighted average of grades in individual tests:

Nf = 40%.T1 + 40%.T2 + 20%.T3

T3 minimum grade is 8/20.

There is a final exam as an alternative to periodic assessments.

Frequency at the discipline implies attending demonstration classes and lecture(s) from industry(es) representative(s).

Subject matter

  1. Review of electromagnetism and electromechanical energy conversion.
  2. Reluctance motors:
    1. Synchronous reluctance motors.
    2. Switched reluctance motors.
  3. Stepper motors.
  4. Special induction motors:
    1. Linear motor.
    2. Single-phase motor.
    3. Variable poles motor.
  5. Permanent magnets motors:
    1. Brushless DC motors.
    2. Synchronous motors.
  6. Superconducting electric machines.


Programs where the course is taught: