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 - 56

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

The distinct concepts, techniques and theories are explained by the lecturer with the support of slides and demonstrators, either implemented in Matlab/Simulink, either real. These are prepared for the classes by the lecturer, and the latter allows verifying or analysing distinct behaviours and operation regimes. One or more lectures by experts in the field are also foreseen.

Students assess their skills through the semiautonomous resolution of sets of problems, available in the slides.

Evaluation is made by means of two tests and a small group project. The final grade consists of the weighted average of these elements. Students who fail must undertake a final exam. This assessment methodology is in accordance with the internal regulation of the faculty.

Evaluation method

Theoretical-practical assessment:

  • Two physical tests: 𝑇(50%) and 𝑇(50%).
  • A minimum grade of 7 on the second test.
  • Final exam, with grade TE  (100%), for those that don''t succeed in the tests.

Subject matter

  1. Review of electromagnetism and electromechanical energy conversion.
  2. Switched reluctance motors.
  3. Special induction motors:
    1. Linear motor.
    2. Single-phase motor.
    3. Variable poles motor.
  4. Permanent magnets motors: Brushless DC motors.
  5. Modelling of electrical machines by the finite elements method.
  6. Superconducting electric machines.


Programs where the course is taught: