Course syllabus

Course-PM

MTT040 MTT040 High voltage technology lp1 HT23 (7.5 hp)

Course is offered by the department of Electrical Engineering

Teachers

Activity	Name	Tel.ext.	name@chalmers.se
Examiner and lecturer	Yuriy Serdyuk (YS)	1624	yuriy.serdyuk
Lecturer	Xiangdong Xu (XX)	1641	xiangdong.xu
Invited Lecturer	Elisabeth Lindell (AL)          ABB Corporate Research, Vasterås, Sweden
Invited Lecturer	Andreas Küchler (AK) University of Applied Sciences Würzburg-Schweinfurt, Germany
Invited Lecturer	Espen Doedens (ED)    Nexans, Norway
Invited Lecturer	Tord Bengtsson (TB)        Hitachi Energy, Vasterås, Sweden
Invited Lecturer	Thomas Hammarström (TH) Chalmers EPE	1649	thomas.hammarstrom
Tutorials, workshop	Yuriy Serdyuk, Xiangdong Xu
Project work	Yuriy Serdyuk
Lab. exercise 1 (Electric breakdown)	Daniel Svensson               Moon Moon Bordeori	5092 1506	daniesve moonmoon.bordeori
Lab. exercise 2 (Diagnostics)	Daniel Svensson               Moon Moon Bordeori	5092 1506	daniesve moonmoon.bordeori
HV laboratory manager      Electrical safety	Thomas Hammarström

Course purpose

The course aims at preparing students to carry out engineering tasks involving design, laboratory testing as well as maintenance of high voltage components in power systems and in other technological applications through understanding of the physical phenomena involved. Focus is set on selection of adequate processes and materials that yield desired electric properties (breakdown and flashover strength, ionization, conduction and polarisation). Based on this understanding, the knowledge on design criteria for insulation dimensioning and on principles for insulation diagnostics is built, including elucidation of basic differences in insulation systems for ac and dc applications. 

After successful completion of the course, a student is well prepared to carry engineering tasks involving apparatus design, laboratory testing as well as maintenance of high voltage components in power systems and in other technological applications. Together with the course MTT035 High voltage engineering (recommended), the present course constitutes a solid base for post-graduate studies within electrical power engineering.

 The course is composed of lectures, tutorials, laboratory experiments and project work. In addition, a study visit to Hitachi Energy production facilities in Ludvika is included to demonstrate manufacturing of high voltage devices and their testing.

Lectures and tutorials cover the following topics:

• Electric fields: field distribution in practical dielectric systems, capacitance calculations; geometric, capacitive and resistive field grading; finite element method (FEM) for field calculations.
• Breakdown mechanisms: in vacuum, gaseous, liquid and solid dielectrics;  streamer mechanism, corona, electronegative gases, arc discharge, arc interruption techniques in gases; bubble and particle initiated breakdown in liquids; intrinsic, thermal and partial discharge initiated breakdown; treeing in solids.
• Conduction and polarization: mechanisms of conduction and polarization in insulating media, dielectric response, concepts of resistivity (conductivity), permittivity and dielectric losses.
• Insulation materials and systems: insulation systems in practice, organic and inorganic materials for insulation, impregnated insulation, composite insulation, ageing and life expectancy.
• DC insulation: materials for DC applications, capacitive and resistive field distribution including transient states, influence of surface and space charges, principles for measuring charge distribution, influence of a thermal gradients.
• Advanced measuring techniques and diagnostics: measurements of resistivity, dielectric response and partial discharges (PDs), characterization of dielectric systems by means of dielectric response, Schering bridge, non-electric detection and localization of PDs, PD-pattern and fault recognition.

• Phenomena at interfaces: electric strength of insulating systems containing interfaces, outdoor insulation, pollution flashover, composite insulators.

Two laboratory exercises (Lab1 and Lab2) and one demonstration (D1) are included:

• Electrical discharges and electric breakdown in air (Lab1),
• Diagnostics of insulation systems (Lab2)
• Electric conduction and polarization workshop (D1).

Project work is included to consolidate the knowledge on electric field calculations. Software COMSOL Multiphysics is introduced as a tool. The subjects for the course project are:

• Transformer bushings,
• Cable termination,
• Overhead lines and cables,
• Insulators for polluted environment.

Schedule

TimeEdit

Course literature

Andreas Küchler, “High Voltage Engineering. Fundamentals, technology, applications”, Springer Verlag, Germany, 2018, ISBN 978-3-642-11992-7 (electronic version is available via Chalmers library). The chapters recommended for reading before lectures are indicated in the schedule below. Handouts of the lecture materials will be available on the course website.

Course design

The teaching is pursued in form of lectures (42h), tutorials (10h), project work (10h), demonstration (4h), laboratory exercises (2x4h) and a study visit. A project reporting session (4h) and exam consultation (2h) are also included. Participation in the lectures and tutorials is voluntary, but highly recommended. The laboratory exercises, demonstration, project work and study visit are compulsory. The course materials, including handouts and labs descriptions, are available for the course participants on the course website in Canvas.

Laboratory experiments (compulsory)

Two compulsory laboratory experiments (4h each) are included in the course. The exercises aim at providing insight on (i) development of electrical discharges in air, and (ii) classical diagnostic methods for quality assessment of insulation systems.

Before participating in the experiments in the high voltage laboratory, each student must study safety instructions and complete a quiz (provided in a special module in Canvas), and thereafter follow the rules exactly.

The laboratory exercises will take place during weeks 36-37 (Lab 1: discharges and breakdown in air, starts from 11/09) and weeks 39-40 (Lab 2: insulation diagnostics, starts 30/09). Time booking for the laboratory exercises is to be made through the course web page. The exercises are to be held in the High Voltage Laboratory (EPE, room 2506).

NOTE! Students will not be allowed to proceed with the exercises without being adequately prepared. The same applies to late arrivals. A lab reports should be prepared after each of the exercises for final approval.

- The deadline for submission of project reports is 16/10 23:59 (reports to be sent to yuriy.serdyuk.chalmers@analys.urkund.se).

- The deadline for submission home assignments is 13/10 23:59 (reports to be sent to yuriy.serdyuk.chalmers@analys.urkund.se).

Learning objectives and syllabus

Learning objectives:

• Recognize various types of apparatuses and insulators in high voltage substations and networks and explain phenomena leading to their failure; understand criteria for insulator selection.
• Identify insulating materials and systems most frequently used in high voltage technology and characterise their advantageous and disadvantageous properties.
• Calculate or estimate electric field strength and its distribution in real insulation systems exposed to ac and dc high voltages; analyse the importance of geometrical design for optimizing electric field distributions.
• Apply computer based tools for solving complex field distribution problems in various high voltage components; demonstrate the outcomes of your simulations and communicate them to other students.
• Possess knowledge on allowable working electric stresses in different insulation systems.
• Be acquainted with different methods for controlling electric field distribution in high voltage devices.
• Explain physical mechanisms responsible for various types of electric discharges in gases with special emphasis to streamer, barrier (partial), surface and arc discharges.
• Describe the influence of different parameters, like electrode geometry, temperature, humidity and pressure, on the electric strength in different insulating materials.
• Evaluate risk for appearance of partial discharges in insulation systems containing defects.
• Define and describe the mechanisms of electric conduction, polarization and breakdown in gaseous, liquid and solid insulating materials (dielectrics).
• Identify the dielectric response in insulating materials an systems; explain how measurements of dielectric response can be used for diagnostics of high voltage devices.
• Recognize environmental risks imposed by different materials used in high voltage technology, propose ways to achieve sustainable solutions, reflect over technical choices from ethical perspective and sustainable aspects.
• Summarize and discuss the outcome of the performed project in a scientific report in an ethically justifiable manner related to plagiarism and authorship.

Link to the syllabus on Studieportalen.

Study plan

Examination

To receive a final grade, approved written examination, laboratory exercises, workshop and project work are required.