Power System Disturbances

Higher education teachers: Mihalič Rafael
Credits: 6
Semester: winter
Subject code: 64217

Subject description


Enrolment to the class

Content (Syllabus outline):

Normal and emergency conditions in electric power systems (EPS), current and voltage stresses in EPS, significance of current stresses determination in EPS for dimensioning process as well as earth and phase overcurrent protection coordination, physical background of phenomena during phase-to-phase and earth faults, phase-to-phase and earth-fault currents calculation by applying symmetrical components approach, calculation of characteristic fault parameters according to appropriate standards, principles and methods for phase-to-phase and earth-fault current calculation applying computer software tools, electrical conductor interruption, methods and reasons for neutral-point earthing, impact of neutral earthing on earth-fault currents and switching overvoltages in EPS, basic principles of fault currents switching and description of physical conditions in switching devices during fault current switching.

Objectives and competences:

Gaining knowledge regarding line-to-line and earth-faults origin, capability for applying phase-to-phase and earth-fault current calculations methods, knowledge regarding application of line-to-line and earth-fault currents calculation results in dimensioning process of EPS elements and overcurrent protection coordination, mastering methods for restraining/limiting line-to-line and earth-fault currents, identifying and understanding EPS parameters influencing fault-current level.

Intended learning outcomes:

Student obtains knowledge about physical background of phenomena leading to appearance of overvoltages and current overloading in EPS (line-to-line faults, earth-faults). Further, knowledge regarding significance of fault-current calculation for dimensioning process of EPS elements and setting-up overcurrent protection. Student will be able to calculate fault currents according to standards, understand methods for EPS neutral-point handling and basic methods as well as physical principles for elimination of EPS elements that represent a source of system disturbances.

Learning and teaching methods:

Lectures and laboratory practice

Study materials


  1. Roeper, Richard: Kratkostični tokovi v trifaznih omrežjih :časovni potek in izračun veličin, Ljubljana : Fakulteta za elektrotehniko, 1987
  2. International standard IEC 60909: Short-circuit currents in three-phase a.c. systems
  3. I. Papič, P. Žunko: Elektroenergetska tehnika I, Založba FE in FRI, 2005.
  4. Das, J. C.: Power system analysis : short-circuit load flow and harmonics, New York : Marcel Dekker, cop. 2002.

Study in which the course is carried out

  • 1 year - 2nd cycle - Electrical Engineering - Electrical Power Engineering