Generators and Transformers

Course description

The losses in the core, windings and additional losses in generators and transformers. Type of  windings (Y, D, Z). Magnetization problems of generators and transformers. Dynamic analysis of short circuits in generators and transformers.

Inrush phenomenon of generators and transformers. Various types of cooling (ONAN, ONAF, OFAF …). Attenuation of short circuits.

Basic tests of generators and transformers. Monitoring the aging of insulation in generators and transformers.
Operating conditions (isolated operation, operating on a rigid network, synchronous compensator). Oscillations in generators. Synchronous reactance. Transient reactance. Sub-transient reactance. “Per-unit” system. Generators and transformers presented by symmetrical components.

Course is carried out on study programme

Elektrotehnika 2. stopnja

Objectives and competences

Acquiring in-depth knowledge of different types of generators and transformers, their properties, design features and applicability.

Learning and teaching methods

Lectures, demonstrations, work with computer tools, laboratory work, coursework, project work.

Intended learning outcomes

After successful completion of the course, students should be able to:

-present the problem of magnetization in generators and transformers,

-explain the transient phenomena in generators and transformers

-apply experiments of generators and transformers for their characterization,

– analyze short circuits within generators and transformers,

– illustrate generators and transformers with symmetric components.

-clarify the operating conditions of generators and transformers (island operation, operation on a rigid network, synchronous compensation).

Reference nosilca

  1. VUKOTIĆ, Mario, MILJAVEC, Damijan. Design of a permanent-magnet flux-modulated machine with a high torque density and high power factor. IET electric power applications, ISSN 1751-8660, 2016, vol. 10, iss. 1, str. 36-44.
  2. VIDMAR, Gregor, MILJAVEC, Damijan. A universal high-frequency three-phase electric-motor model suitable for the delta and star winding connections. IEEE transactions on power electronics, ISSN 0885-8993, Aug. 2015, vol. 30, no. 8, str. 4365-4376.
  3. VIDMAR, Gregor, MILJAVEC, Damijan, AGREŽ, Dušan. Measurement and evaluation of EDM bearing currents by the normalized Joule integral. Measurement science & technology, ISSN 0957-0233, 2014, vol. 25, no. 7, str. 1-10.
  4. GOTOVAC, Gorazd, LAMPIČ, Gorazd, MILJAVEC, Damijan. Analytical model of permeance variation losses in permanent magnets of the multipole synchronous machine. IEEE transactions on magnetics, ISSN 0018-9464, Feb. 2013, vol. 49, no. 2, str. 921-928.
  5. JEREB, Peter, MILJAVEC, Damijan. Vezna teorija električnih strojev. 1. izd. Ljubljana: Fakulteta za elektrotehniko, 2009.

Study materials

  1. Jereb Peter, Damijan Miljavec: Vezna teorija električnih strojev, Založba FE in FRI 2008
  2. Bharat Heavy Electricals Limited: Transformers, McGraw-Hill, 2005
  3. S.V. Kulkarni, S.A. Khaparde: Transformer Engineering, Marcel Dekker, Inc., 2004
  4. James H. Harlow: Electric Power Transformer Engineering, CRC Press, 2003
  5. Aa. Carlson, J. Fuhr, G. Schemel, F. Wegscheider: Testing of Power Transformers,
    1. Pro Print GmbH for ABB, Düsseldorf, 2003
  6. Ion Boldea Variable Speed Generators, Taylor & Francis, 12. dec. 2010.
  7. Juha Pyrhonen, Tapani Jokinen, Valeria Hrabovcova, Design of Rotating Electrical Machines, John Wiley & Sons, 2009.

Bodi na tekočem

Univerza v Ljubljani, Fakulteta za elektrotehniko, Tržaška cesta 25, 1000 Ljubljana

E: T:  01 4768 411