Electrotechnical Measurements

Course Description

Basic measurements and testing of electrical machines, transformers and power systems. Current and voltage measuring transformers. Design and types of measuring transformers. Testing and error determination of measuring transfomers. Partial discharge measurements. In-situ insulation measurements of power equipment. Nonconventional measuring transformers. Methods of high DC and AC current measurements. Grounding systems. Measurement of earth ground resistances and soil resistivity. Diagnostics of power cables and lines. High voltages (HV) generation in switchgear. Lightning strokes and lightning location systems. Insulation coordination. Generation and measurement of HV AC, impulse voltages and HV DC in HV laboratory. Generation and measurement of impulse currents. Methods and procedures of HV measurement and testing: spark gap; capacitive and resistive dividers, current shunts.

General Competencies

Fundamental knowledge in field of measurements of electrical quantities in high voltage and power systems.

Learning Outcomes

  1. distinguish measurement methods of electrical quantities in power systems
  2. define and measure characteristics of measuring transformers
  3. apply nonconventional methods in high current measurements
  4. produce reliable earth grounding systems
  5. identify breakdowns in power cables and lines
  6. identify the high voltage transformers and generators in laboratory and in service
  7. analyze the results of HV testing
  8. apply the data from lightning location systems

Forms of Teaching

Lectures

The classes is organized in two teaching cycles. The first cycle consists of seven weeks of classes and exam, while second cycle includes six weeks of classes and a final exam. Teaching is carried out through a total 15 weeks with load of 2 hours.

Experiments

Within the course, it will be shown a few demonstration exercises of the high voltages and current measurement.

Grading Method

Continuous Assessment Exam
Type Threshold Percent of Grade Threshold Percent of Grade
Homeworks 0 % 20 % 0 % 20 %
Quizzes 0 % 20 % 0 % 20 %
Mid Term Exam: Written 0 % 30 % 0 %
Final Exam: Written 0 % 30 %
Exam: Written 0 % 30 %
Exam: Oral 30 %

Week by Week Schedule

  1. Introduction Basic measurements of electrical quantities in power systems Measuring transformers
  2. Inductive voltage transformer, voltage and phase error Current transformer, current and phase error Types of measuring transformers
  3. Testing of magnetic properties of transformer core Measurement of power losses in transformer core and windings Partial discharge measurements
  4. Measurement of measuring transformer errors (compensatory and differential methods) Capacitance and loss factor measurements due to insulation characterisation
  5. DC Current transformer principle Transformers with compensated magnetic fluy (Hall sensor) Nonconventional current measurement transformer (Rogowski coil)
  6. Grounding systems Grounding resistance measurements methods (UI method, Behrend method, Nippold method) Soil resistivity measurements method
  7. Power cable fault diagnostic methods (Murray method, Varley method, Heinzelmann method) Fault location measurements (reflectometric method, induction method)
  8. Exam
  9. Exam
  10. Operation of the power system. High voltage transmission lines and isolation. Why high voltage (HV)? What is HV?
  11. Generation of HV AC? Generation of impulse voltages? Lightning location systems. Insulation coordination.
  12. Generation of HV AC in HV laboratory. Measurement of HV AC in switchgear. Measurement of HV AC in HV laboratory. Experiments in HV laboratory.
  13. Generation and measurement of impulse voltages. Impulse generator. Experiments in HV laboratory. Working principle of surge arresters.
  14. Testing with impulse currents. Impulse current generator. Shunts for impulse current measurements. Experiments in HV laboratory.
  15. HV DC. Generation. Measurement of HVDC. Experiments in HV laboratory.

Study Programmes

University graduate
Electrical Engineering Systems and Technologies (profile)
Recommended elective courses (3. semester)

Literature

V. Bego (2003.), Mjerenja u elektrotehnici, Graphis
V. Bego (1977.), Mjerni transformatori, Školska knjiga, zagreb
J. Webster (1999.), Measurement, Instrumentation and Sensors Handbook;J. Webster;1999;CRC Press, CRC Press
M. S. Naidu, V. Kamaraju (2009.), High Voltage Engineering, Tata McGraw-Hill
E. Kuffel, W. S. Zaengl, J. Kuffel (2000.), High Voltage Engineering: Fundamentals, Newnes

General

ID 34425
  Winter semester
4 ECTS
L0 English Level
L1 e-Learning
30 Lectures
0 Exercises
0 Laboratory exercises
0 Project laboratory

Grading System

90 Excellent
79 Very Good
67 Good
55 Acceptable