# Reliability in electrical power engineering

## Subject description

Basic principles of reliability, safety, risk and their mutual relationship.

Basics of probability theory, set theory and Boolean algebra.

Measures of reliability and safety of facilities and devices. Risk criteria. Risk informed decision making.

Methods for assessment reliability and safety – theory and examples: loss of load probability, distribution indices (system average interruption frequency index, system average interruption duration index), effective load carrying capability, fault tree, event tree.

Common cause failures – methods and examples.

Improvement of reliability of power systems and devices: redundancy, independence, separation, fail-safe principle, single failure criterion.

## Objectives and competences

Students will obtain basic information about safety and reliability in electrical power engineering. They will learn the basic methods and indices about assessment of reliability. They will get knowledge about importance of reliability of particular components and overall systems and their impact to safety and economics of specific facilities or systems. The safety culture will be emphasised and responsibility for safe and reliable use of energy will be stimulated.

## Teaching and learning methods

Lectures or individual consultations, supervisor of seminar work

## Expected study results

Ability of assessment of improvement of reliability with consequent increase of related costs. Judgement of efficiency of future investments to real power systems considering improvement of reliability indices and consequently increased costs.

## Basic sources and literature

1. M. Čepin, Assessment of Power System Reliability, Springer, 2011
2. M. Čepin, Probability of restoring power to the transmission power system and the time to restore power, Reliability engineering & systems safety, 2020, Vol. 193, 106595
3. M. Čepin, Contribution of human reliability in power probabilistic safety assessment models versus shutdown models. ASCE-ASME journal of risk and uncertainty in engineering systems, Part B, Mechanical engineering, 2020, 011001
4. M. Čepin, The extended living probabilistic safety assessment. Proceedings of the Institution of Mechanical Engineers, Pt. O, Journal of risk and reliability, 2020, Vol. 234 (1), str. 183-192
5. M. Čepin, Evaluation of the power system reliability if a nuclear power plant is replaced with wind power plants, Reliability engineering & systems safety, 2019, Vol. 185, str. 455-464

## Stay up to date

University of Ljubljana, Faculty of Electrical Engineering Tržaška cesta 25, 1000 Ljubljana