# Power System Dynamic Phenomena

## Course description

Basic facts and ground reasons behind electric power system (EPS) dynamic phenomena occurrence, categorization of different dynamic phenomena, basic principles for analysis of each phenomenon type, EPS elements modelling principles for different time-scale dynamic phenomena, small-signal stability EPS analysis (linear state-space modelling, eigenvalues, system controllability and observability, etc.), methods for discrete-time systems analysis, approaches to non-linear systems dynamic phenomena analysis, analysis of typical and most common types of EPS dynamic phenomena (oscillations, transient stability, frequency stability, travelling waves, asynchronous operation of a synchronous machine, transient phenomena within a synchronous machine, short-circuit events in EPS, impact torque on synchronous generators as a consequence of different EPS events, capacitive-current switching, sub-synchronous resonance), measures for the stabilization of EPS operation, basic principles of dynamic phenomena digital simulation techniques, equivalent circuits of different EPS elements, numerical instability issues and measures for its avoidance, setting-up EPS model initial conditions, setting-up initial conditions for a composite model synchronous generator – governor – exciter, basic characteristics of dynamic simulation software tools, momentary mode dynamic simulations, stability mode dynamic simulations, real-time dynamic simulations.

## Objectives and competences

The objective of the course on Power System Dynamic Phenomena is to to provide an understanding of the physical background of the origin and the conditions of operation of an EPS, which may lead to the appearance of certain dynamic phenomena in an EES. These can be the cause of the operational problems in EPSs and, as it turned out, was one of the main causes for the blackouts in the past. Therefore, the students should also get acquainted with some examples and get a "feeling" of the consequences for which the problem of instability of the EES can be caused in operation. In the mathematical treatment of phenomena, the attention is given the practical application of mathematical knowledge in the field of differential calculus and the understanding of the mathematical background in describing physical phenomena and their simulation. This is a prerequisite for the competent use of the relevant simulation software tools.

## Learning and teaching methods

Lectures and practical laboratory courses. Part of the pedagogical process will be carried out with the help of ICT technologies and the opportunities they offer.

## Intended learning outcomes

After successful completion of the course, students should:

• understand the causes of selected dynamic phenomena in an EPS and their influence to an EPS operation,
• know the types of stability of an EPS and stability categorization regarding dynamic phenomena characterising them,
• get to know and use mathematical approaches for considering various stability categories,
• be able to use software tools for simulating dynamic phenomena in EPS.

## Reference nosilca

1. MIHALIČ, Rafael. Stabilnost in dinamični pojavi v elektroenergetskih sistemih : osnovni pojmi s primeri. Ljubljana: Slovensko združenje elektroenergetikov CIGRÉ – CIRED, 2013.
2. RUDEŽ, Urban, MIHALIČ, Rafael. Analysis of underfrequency load shedding using a frequency gradient. IEEE transactions on power delivery, vol. 26, no. 2, str. 565-575.
3. MIHALIČ, Rafael, GABRIJEL, Uroš. A structure-preserving energy function for a static series synchronous compensator. IEEE transactions on power systems, vol. 19, no. 3, str. 1501-1507.
4. RUDEŽ, Urban, MIHALIČ, Rafael. Monitoring the first frequency derivative to improve adaptive underfrequency load-shedding schemes. IEEE transactions on power systems, 2011, vol. 26, no. 2, str. 839-846.
5. GAŠPERIČ, Samo, MIHALIČ, Rafael. The impact of serial controllable FACTS devices on voltage stability. International journal of electrical power & energy systems, Jan. 2015, vol. 64, str. 1040-1048.

## Study materials

1. MIHALIČ, Rafael. Stabilnost in dinamični pojavi v elektroenergetskih sistemih : osnovni pojmi s primeri. Ljubljana: Slovensko združenje elektroenergetikov CIGRÉ – CIRED, 2013. 261 str., ilustr. ISBN 978-961-6265-23-2.
2. Kundur P., Power System Stability and Control, McGraw Hill, 1994.
3. Machowski J. Bialek J. W., Bumby J. R., Power System Dynamics and Stability, John Wiley & Sons, 1997.

## Bodi na tekočem

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