Switching and Protection Devices

Course Description

Definitions and the classification of switching and protection devices. The classification according to the rated voltage, function, current breaking system and the protection or circuit control function. Basic functioning principles. Characteristics and types. Protection in the low- and medium voltage electrical distribution systems. Protection coordination. Switching in an electrical network, motor, transformer, generator protection and other protections. Communication and interface subsystems the connection of control devices. Environmental conditions, sources of disturbances, protection measures. Standards, testing, maintenance.

General Competencies

In-depth knowledge of switching and protection devices. Deep understanding of general theory of switching and protection devices. Insight of current breaking systems and principles of power engineering system protection. Capability to determine the parameters of switching and protection devices.

Learning Outcomes

  1. define functions of the switching and protection devices,
  2. choose low-voltage switching and protection devices,
  3. choose measurement transformers for protection device connection,
  4. choose protection system of MV industrial network,
  5. choose protection system of low-voltage industrial network,
  6. choose time coordination method for power system protection.

Forms of Teaching

Lectures

Lectures will be held two hours a week with the use of PowerPoint presentations and overhead projectors.

Laboratory Work

Laboratory exercises will be held in one cycle in the Laboratory of relay protection.

Seminars

During semester, students will create one seminar.

Internship visits

During semester there will be a technical visit to the Končar factory.

Grading Method

     
Continuous Assessment Exam
Type Threshold Percent of Grade Threshold Percent of Grade
Laboratory Exercises 0 % 10 % 0 % 10 %
Seminar/Project 0 % 20 % 0 % 20 %
Mid Term Exam: Written 50 % 20 % 0 %
Final Exam: Written 50 % 50 %
Exam: Written 50 % 50 %
Exam: Oral 20 %

Week by Week Schedule

  1. Definitions and the classifications of switching and protection devices.
  2. Functions of the switching and protection devices – circuit making and breaking, starting, regulation, protection and circuit control.
  3. Classification switching devices according to the function – disconnectors, switches, contactors, circuit breakers, starters, regulators, fuses, surge arrestors, relays, tripping devices, high and low voltage switchgear, grounding devices; the classification according to the rated voltage, current breaking system and the protection or circuit control function.
  4. Physics base of the switching devices, electrical contacts, direct and altering current interruption, basic technical characteristics – breaking and making capacity, rated current and rated voltage mechanical and electrical endurance.
  5. Low-voltage switching and protection devices; disconnectors, switches, contactors, residual current devices, fuses, surge arrestors, motor starters characteristics and choice.
  6. Low-voltage switchgear and control-gear, definitions and functions.
  7. Protections and other functions of the switching and protection devices; overload protection, short-circuit protection, protection against electric shocks, residual current protection, under-voltage protection.
  8. Short-circuit current limiting, amplitude and breaking time limiting.
  9. Protection coordination selectivity.
  10. Executions and characteristics of the tripping devices and relays.
  11. High-voltage devices and switchgear, disconnectors, switch-disconnectors, circuit breakers, fuses and high voltage substations.
  12. Protection of electrical networks, transformers, generators, bus-bars and motors in industrial power systems.
  13. Choice of the measurement transformers for protection device connection.
  14. Numerical relays execution; over-current, voltage, distance, differential relays.
  15. Installations, testing, maintenance, monitoring of the switching and protection devices.

Study Programmes

University graduate
Electrical Engineering Systems and Technologies (profile)
Specialization Course (1. semester) (3. semester)

Literature

B. Belin (1978.), Uvod u teoriju električnih sklopnih aparata, Školska knjiga, Zagreb
A. Marušić (2006.), Zaštita elektroenergetskog sustava, Skriptarnica FER, Zagreb
Siemens AG (1994.), Switching, protection and distribution in low-voltage networks, MCD Verlag, Munchen
K. Meštrović (2007.), Sklopni aparati srednjeg i visokog napona, Graphis, Zagreb

Laboratory exercises

General

ID 86525
  Winter semester
4 ECTS
L1 English Level
L1 e-Learning
30 Lectures
0 Exercises
15 Laboratory exercises
0 Project laboratory

Grading System

90 Excellent
75 Very Good
60 Good
50 Acceptable