Dear Student,

Welcome to the high voltage course starting on Tuesday 08:00 in Zoom. I hope that I will manage to share my enthusiasm for this intriguing subject with you during the coming two months!

Unfortunately the covid-19 pandemic will affect the format of the course. All lectures will be given on Zoom. The exercises will be hopefully be held on campus (HC1) considering social distancing, but can also be followed on Zoom - however, this set-up can be subject to a sudden change if the covid-19 situation gets worse. The two four-hours laboratory exercises will be carried out in groups of five students wearing visors at campus.

Please give me feedback and proposals for improvements during the course. Distance education is difficult for both students and teachers and I have not taught in this way before.

Best regards,

Jörgen Blennow, examiner

 

Course-PM

MTT035 High voltage engineering lp2 HT20 (7.5 hp)

Course is offered by the department of Electrical Engineering

Contact details

Examiner, lecturer: Jörgen Blennow, jorgen.blennow@chalmers.se

Lecturer: Xiangdong Xu, xiangdong.xu@chalmers.se

Tutor/exercises: Chengjun Tang, chengjung.tang@chalmers.se

HV-lab/safety manager: Thomas Hammarström, thomas.hammarstrom@chalmers.se

Lab 1: Lightning impulse testing: Mohammad Kharezy, kharezy@chalmers.se, Xiangdong Xu, xiangdong.xu@chalmers.se Jörgen Blennow jorgen.blennow@chalmers.se

Lab 2: Overvoltages in cables: Chengjun Tang, chengjun.tang@chalmers.se Ahmed Sunjaq, sunjaq@chalmers.se Jörgen Blennow jorgen.blennow@gmail.com

Guest lecture "Challenges in HV measurements": Karin Cedergren & Joni Klüss, RISE - Research Institutes of Sweden

 

In the course the following student representatives have been appointed:

TIELL               nour.ne9@gmail.com             Nour Aldeen Alassadi

TIELL               abshir97@hotmail.se              Abshir Omar Hasan

MPEPO             johsi@student.chalmers.se     Simon Johansson

MPEPO             niharika.tsr@gmail.com         Niharika Sharma

MPEPO             janaveer6@gmail.com           Janarthanan Veerasamy

 

Course purpose

For the student this course represents the first contact with the diverse subject of high voltage engineering. It mainly aims at: i) introducing fundamental concepts and providing basic understanding within the area of classical experimental high voltage engineering; ii) familiarising the student with the electric power system on a component level and iii) preparing the student for the second course High Voltage Technology which is essential for the student wishing to achieve a broader and deeper understanding of the subject. After successful completion of the two courses in high voltage engineering as a part of the electric power programme the student is well prepared for a carrier e.g. as a R&D-engineer of high voltage design and laboratory activities or as a qualified engineer dealing with various aspects of the components in the power system. In addition, the two courses together constitute a solid base for post-graduate studies in electric power engineering.

Schedule

TimeEdit

Course literature

• Andreas Küchler, High Voltage Engineering, Fundamentals - Technology - Applications. ISBN 978-3-642-11992-7 or ISBN 978-3-642-11993-4 (e-book), Available at Store but also as e-book through Chalmers library.

or

• Kuffel, W. S. Zaengl, J. Kuffel: High Voltage Engineering: Fundamentals, 2^nd ed. 2000, Newnes, ISBN 0 7506 3634 3. Available as e-book through Chalmers library.

and

• R. Hileman: Insulation Coordination for Power Systems, 1999, CRC Press, ISBN 0-8247-9957-7 (available as e-book through Chalmers library).
• High Voltage Engineering, Tutorial exercises (uploaded on Canvas).
• Additional course material uploaded on Canvas.

As a complement, F.H. Kreuger, Industrial high voltage, Vol. I 1991 (ISBN 90 6275 561 5) and Vol. II 1992 (ISBN 90 6275 562 3), Delft University Press, can be read in parallel.

Course design

The teaching is pursued in form of lectures (36h), tutorials (30h), laboratory exercises (8h) but also as self-studies (126h). Participation in lectures and tutorials are voluntary but highly recommended.

A voluntary trial exam will not be arranged the academic year 2020/2021 due to the covid-19 pandemic.

All lectures will be given on Zoom. The exercises will be hopefully be held on campus (HC1) considering social distancing, but can also be followed on Zoom - however, this set-up can be subject to a sudden change if the covid-19 situation gets worse. The two four-hours laboratory exercises will be carried out in groups of five students wearing visors at campus.

The lecture and tutorial/exercise plan is included in the course-pm document uploaded on Canvas.

Two four-hours laboratory exercises (including brief lab-preparation reports) are compulsory. Only one group of students can work in the high voltage laboratory at the same time which results in about 10 laboratory occasions á 4 hours for each of the two labs. If a laboratory session is not appropriate prepared the student is not allowed to conduct it.

A compulsory and individually written reflection on group diversity should be handed in (deadline 20th December 2020)

Changes made since the last occasion

The result of the course evaluation previous year is accessible from this link:

https://course-eval.portal.chalmers.se/SR/Report/Token/15881/0/0e09f551-1ce9-424e-a2bc-763cc9aeb204.

Most things worked fine and should be kept. A few things should be changed, see below. Suggested changes:

• Stress that it is important to take part in the tutorials and that they are complementary to the lectures.
• The timing opening of the lab registration in the CANVAS page (i.e. possibility to choose the lab group/lab slot)

Learning objectives and syllabus

Learning objectives:

• perform analytical calculations of the electric field distribution in insulation systems having plane-parallel, coaxial and spherical geometries.
• point out un-suitable geometries where the field locally will be very high and suggest improvements of design.
• explain the mechanism of electric breakdown in gases under low pressures by using a simple ballistic collision model (Townsend's breakdown mechanism).
• define mean free path, Townsend's first and second ionization coefficients and the breakdown criteria.
• explain, from an engineering point of view, and point out parameters important for obtaining high electric withstand strength.
• apply the Paschen curve for estimating the electric strengths of short homogenous gas gaps under low pressure and varying ambient conditions.
• explain the influence of time lags on breakdown voltage and explain the implications on insulation coordination.
• demonstrate familiarity with the characteristics of laboratory equipment for generation and measurement of high voltages by making a well-motivated choice for a specific test situation or test purpose.
• plan and physically arrange a high voltage test set-up in a safe way and be able to minimize and assess risks with respect to personal safety and integrity of measuring circuits and instruments.
• use high voltage test procedures for finding breakdown and withstand voltages.
• statistically evaluate such performed test sequences and make necessary atmospheric corrections.
• identify electric power components in a substation and explain their role in the station and their characteristics, and, give examples on how digital solutions might change the classical substation.
• compare and discuss advantages/disadvantages of using equipment of different design or working principles.
• identify and explain different construction elements of overhead and cable lines.
• calculate the probable number of annual faults for an overhead line due to direct hits to the line according the Rolling sphere theory and considering the risk of back-flashovers.
• calculate overvoltages caused by travelling waves and reflections in the power system and demonstrate how surge arresters can be used to limit these.
• explain and schematically illustrate different origins of switching and temporary overvoltages and their characteristics.
• demonstrate insight in, and under guidance of an experienced engineer be able to coordinate the insulation level of specific apparatus with respect to over voltages occurring at a specific position in the system with the use and appropriate choice of protective measures in order to achieve (calculate) a technical/economical acceptable risk.
• identify and discuss technologies that might have a negative impact on environment and human health. Such examples can be choice of insulation media, exposure to electromagnetic fields, acoustic noise and visual appearance.
• reflect on opportunities and challenges of an international working environment.

Link to the syllabus on the Student Portal:

Study plan

Examination format

For receiving final grade, approved final written examination and approved laboratory exercises (including short reports) have to be fulfilled. In addition, a compulsory and individually written reflection on group diversity should be handed in (deadline 20th December 2020)

The written examinations take place on:

• Wednesday 13^th January 2021, J, 14:00-18:00 hrs
• Friday 9^th April 2021, J, 14:00-18:00 hrs
• Wednesday 18^th August 2020, J, 14:00-18:00 hrs

An exam with illegible handwriting will be marked as failed. Assumptions, quantities and symbols introduced must be motivated and defined. Always focus your answer on the question asked and do not try to write as much as possible about related subjects. Put the papers well-ordered, with the paper header correctly filled in, in the exam enclosure. English is the only accepted language.

The total number of points of the written examination will be 50 of which about 50% are of a descriptive nature and about 50% are of a calculative nature.

Means allowed: Physics Handbook, Beta Mathematics Handbook, Chalmers approved calculator and printed language dictionaries (i.e. books, not electronic ones). No notes in the aids are allowed.

Grades: 5: 40p (80%); 4: 30p (60%); 3: 20p (40%); Failed < 20p (<40%) according to the Chalmers’ grading system.

Note: Most probably the format of the exam needs to be changed due to the covid-19 pandemic into a distance exam using Canvas with Zoom monitoring and with all aids allowed. More instructions will follow during the course.

For obtaining the final grade in the course the two compulsory laboratory experiments (about four hours each) must be approved . In order to enhance understanding, short reports must be submitted in conjunction to each laboratory experiment, discussing and concluding the topics of the laboratory. Further instructions are given by the lab-assistants and in the lab-pm.