57950 - Electrical Machines

Academic Year 2009/2010

  • Docente: Giovanni Serra
  • Credits: 6
  • SSD: ING-IND/32
  • Language: Italian
  • Teaching Mode: Traditional lectures
  • Campus: Bologna
  • Corso: First cycle degree programme (L) in Electric Engineering (cod. 0047)

Learning outcomes

The course is proposed to supply the basic knowledge for the study of the widely used electric machines.  The operating principles and the performance in different operating conditions will be analysed.

After passing this course, students will be familiar with issues involved in electromechanical energy conversion, use of mathematical models to predict the machine behaviour, analysis of usual operating conditions.

Course contents

Recalls on the laws of the electromagnetism and on the main property of the conducting, dielectrics and ferromagnetic materials employed in the accomplishment of the electric machines.

Transformers

Basic definitions and construction elements, principle of operation, machine equations, equivalent circuits and performance. Unbalanced duty of three-phase transformers, parallel operation, autotransformers, transformers, test transformers. Machine parameter determination by laboratory tests.

Rotating Machines

General information on AC machines. Windings for alternating current machines.

Induction machines

Rotating magnetic field, equivalent circuits, torque characteristics. Starting of three-phase induction motors, speed control. Single-phase induction motors.

Synchronous machines

Basic types of synchronous machine and operating principle, armature reaction, voltage diagrams, torque production, parallel operation, oscillations of synchronous machines.

DC machines
Basic types of DC machines, magnetic circuit, windings, emf calculation, machine equations. Armature reaction, commutation, compensating windings. Characteristics of DC motors and generators.

Readings/Bibliography

A. E. Fitzgerald, C. Kingsley, A. Kusko: Macchine elettriche. Franco Angeli

E. Di Pierro: Costruzioni elettromeccaniche (vol. I e II). Eedizioni Scientifiche Siderea, Roma

L. Fusco, D. Iannuzzi, E. Pagano, L. Piegari: Macchine elettriche. Liguori Editore, Napoli

M. Kostenko, l. Piotrovsky: Electrical machines, (vol. I e II). Mir Publishers Moscow

Paper copy of the PowerPoint presentation

Teaching methods

The course includes hours of lesson and hours of exercise where application examples are presented.

The proposed exercises need the use of pocket calculators together with tables and graphs from commercial data.

Assessment methods

The final test consists in the overcoming of a written exercise and of an oral discussion based on three of the basic issues of the Course.

Teaching tools

Blackboard, overhead projectors and PC based presentations are employed during lessons.

Simulation software and running models of electrical machines are also available

Office hours

See the website of Giovanni Serra