Course detail

Substations and Lines

FEKT-MKC-ESVAcad. year: 2023/2024

Description of basic parts and accessories of electrical substations. The operation, design and protection of transformers. Earthing system of switchgears and transformer substations. Substation automation system. Theory of thermal and mechanical stress of conductors due to operating loads and short-circuits. Theory of mechanical stress of unsymmetrical hanging conductor under the given climatic conditions. Practical experience, students will gain by working on supply transformer station project and also in laboratory exercises, where they verify the correct setting of transformer differential protection or blocking of apparatus by means of the substation simulator.

Language of instruction


Number of ECTS credits


Mode of study

Not applicable.

Entry knowledge

The basic knowledge of the design of power lines, schemes and versions of switchgears in electrical substation are required. Students registered in the course should be able to describe and explain the principles of operation and equivalent circuit of transformer. Their orientation in the basic principles of functional types of protection is assumed. General knowledge is required at the level of bachelor's degree, but it is advisable to have completed courses Electrical Power Distribution and Distribution Equipment.

Rules for evaluation and completion of the course

Students can obtain up to 50 points of the overall evaluation of the course during the semester - 16 points for projects up to 12 points for the processing of laboratory protocols and 22 points in the final test. A student has to obtain at least half of the maximum points in all mentioned activities.
The final exam is oral (max. 50 points). It focuses on the orientation in the topics as are defined in course syllabus. The condition for the successful passing this exam is to get at least half of the maximum points

Labs are compulsory; correctly excused absence can be replaced by arrangement with the teacher.


The aim of course is to familiarize students with the current state of electrical equipment stations especially at medium and high voltage, with emphasis on operation and protection of transformers. Furthermore, to give information about the current substation automation systems. To give a comprehensive information about the theoretical foundations of designing of switchgears and conductors.
Graduates of this course should be able to
- characterize the basic types of electrical susbstation,
- apply appropriate arrangement of busbar systems of switchgear in the electrical substation project,
- select the appropriate power output and power transformers for substation,
- apply the basic interlocking conditions for the blocking of individual devices in switchgears branches,
- distinguish the devices in individual level of substation automation system,
- describe and explain the transformer protection system,
- calculate the setting of transformer differential protection,
- check power line according to thermal and dynamic effects of short-circuit current,
- design a grounding of transformer station according to the required earthing resistance.

Study aids

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

Orságová, J. Elektrické stanice a vedení. Elektronická skripta. VUT v Brně 2017 (CS)
Toman P. a kol. Provoz distribučních soustav. České vysoké učení technické v Praze Praha 2011. ISBN 978-80-01-04935-8. (CS)

Recommended reading

Tlustý, J. a kol. Monitorování, řízení a chránění elektrizačních soustav . České vysoké učení technické v Praze Praha 2011. ISBN 978-80-01-04940-2. (CS)
Tlustý J. a kol. Návrh a rozvoj elektroenergetických sítí. České vysoké učení technické v Praze Praha 2011. ISBN 978-80-01-04939-6. (CS)


Classification of course in study plans

  • Programme MKC-EEN Master's, 1. year of study, summer semester, compulsory

Type of course unit



26 hours, optionally

Teacher / Lecturer


1. Electric power station - types, basic terms a classification, schemes of AC switchgears
2. Principles of designing of transformer station - installed capacity specification, choice of parameters and arrangement of switchgears
3. Transformers - parameters, operation modes, design criteria for transformer chamber
4. Transformers - transformer protection
5. MV and HV cables dimensioning – flowing current thermal effect
6. Influence of short circuit current on switchgears - theory of thermal and mechanical short circuit strength
7. Overhead line - mechanic of asymmetrically hanging wires, state equation
8. Substation protection - busbar protection, feeder protection
9. Substation automation system – structure, hierarchy, communication according to IEC 61850
10. Instrument transformers dimensioning
11. Substation earthing - fundamentals, definitions and specification
12. Substation earthing - method for measuring of earthing resistance, earthing voltage and touch
13. Ripple control - purpose, principle, commanding code, ripple control signal propagation in power system

Fundamentals seminar

18 hours, compulsory

Teacher / Lecturer


1. Transformers - installed capacity of transformer station, operation in parallel.
2. Transformer station disposition and calculate of cooling in transformer chamber.
3. Dimensioning of transformer station devices - branch equipment, uninterruptible supply.
4. Calculation and check protective earthing system.
5. Waveforms of mechanical effects of short-circuit currents.
6. Calculation of overhead line - various solution of state equation.

Laboratory exercise

12 hours, compulsory

Teacher / Lecturer


1. Feeder terminal - control function and apparatus blocking.
2. Differential protection of transformer -measuring of operating characteristic.
3. Transformers with different ratio and impedance in parallel.
4. Demonstration of the infuence of current transformer burden on correct overcurrent protection function.


9 hours, compulsory

Teacher / Lecturer


1. Program for setting and configuration of feeder terminal.
2. Project of distribution transformer station MV/LV
3. Calculation of installation table for overhead line.