Course detail

Substations and Lines

FEKT-NESVAcad. year: 2016/2017

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

English

Number of ECTS credits

6

Mode of study

Not applicable.

Learning outcomes of the course unit

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.

Prerequisites

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.

Co-requisites

Not applicable.

Planned learning activities and teaching methods

Techning methods include lectures, computer laboratories and practical laboratories. Course is taking advantage of e-learning (Moodle) system. Students have to write two projects/assignments during the course.

Assesment methods and criteria linked to learning outcomes

Students can obtain up to 50 points of the overall evaluation of the course during the semester - 20 points for projects up to 10 points for the processing of laboratory protocols and 20 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

Course curriculum

1. Electrical substations – types, basic terms and classification, fiction relations between individual parts.
2. AC Switchgears – bay types and its equipment, operational manipulation, blocking of apparatus.
3. Installed power of transformer units in supply transformer station project, transformer parameters, project documentation.
4. Transformers operation – voltage drop, parallel operation, loses, overloading, transformer site.
5. Transformer protections – differential protection principle and performance, overloading protections, earth fault protection.
6. Substation automation system – hierarchy, individual level devices, bussbar protections.
7. Substation earthing system – basic terminology, design of earthing system, ground electrodes, earthing of distribution transformer stations MV/LV.
8. Substation earthing system – earthing theory, calculation of simple ground electrodes and earthig systems resistance.
9. Ripple control – purpose, principal and features, impact of power systems elements on ripple control signal transmission.
10. Power lines conductors and cables dimensioning – conductor ampacity, theory of conductor thermal characteristic.
11. Power lines conductors and cables dimensioning – theory of dynamic strength of conductor during the short circuit.
12. Overhead lines – mechanics of unsymmetrical hanging conductor, state equation and its solving possibilities, critical temperature and span.

Work placements

Not applicable.

Aims

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.

Specification of controlled education, way of implementation and compensation for absences

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

Recommended optional programme components

Not applicable.

Prerequisites and corequisites

Not applicable.

Basic literature

NOHÁČOVÁ, L., MERTLOVÁ, J. Electrical Power Station and Lines. BEN -Technická literatura, Praha 2010. ISBN 978-80-7300-265-7 (EN)
STEWART, S.Distribution Switchgear, IEE London 2004 (EN)

Recommended reading

Not applicable.

Classification of course in study plans

  • Programme EECC-MN Master's

    branch MN-EEN , 1 year of study, summer semester, compulsory

Type of course unit

 

Lecture

26 hod., optionally

Teacher / Lecturer

Syllabus

1. Electric power station - types, basic terms a classification, function relation between detail parts.
2. AC switchgears - scheme, busbar system, branch equipment, operatin handling and blocking of switchgear apparatus.
3. Principles of designing of transformer station - installed capacity specification, choice of parameters and arrangement of switchgears.
4. Transformers - parameters, operation modes, design criteria for transformer cells.
5. Transformers - transformer protection.
6. Substation earthing - fundamentals, definitions and specification
7. Substation earthing - method for measuring of earthing resistance, earthing voltage and touch voltage.
8. Influence of short circuit current on switchgears - theory of thermal and mechanical short circuit strength.
9. Substation protection - busbar protection, feeder protection, protection terminal in switchgear control system.
10. Power station operation control - substation automation system, its providing and abilities.
11. Ripple control - purpose, principle, commanding code, ripple control signal propagation in power system.
12. Overhead line - mechanic of asymmetrically hanging wires.
13. Electromagnetic field in the vicinity of substations and lines.

Fundamentals seminar

18 hod., compulsory

Teacher / Lecturer

Syllabus

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.

Exercise in computer lab

9 hod., compulsory

Teacher / Lecturer

Syllabus

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.

Laboratory exercise

12 hod., compulsory

Teacher / Lecturer

Syllabus

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.