Introduction

EE 468
High Voltage Engineering and
Laboratory

Instructor: Dr. Mohammed Alsolami

Spring 2020

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 Text
1.Power point handouts and reference material

2.Book reserve list – has been deposited in the Engineering Library

CALL # AUTHOR TITLE NO.COPIES
QC 711 C65 Cobine, J.D. Gaseous Conductors, 1
(from compact shelves) 1941 (a classical book)

TK 153 G33 1983 Gallagher, T.J. and High Voltage Measurements, 1

Pearmain, A.J. Testing and Design, 1983

TK 153 H53 2010 Abdel-Salam, M., et al High Voltage Engineering: theory and 1
practice, 2010

TK 153 K8 2000 Kuffel, E., High Voltage Engineering 1

Zaengl, W.S. and Fundamentals, 2000
Kuffel, J.

TK 147 K5613 2001 Kind, D. High-voltage Test Techniques 1

2001

TK 3001 N3 2011 Naidu, M.S. and High Voltage Engineering, 1

Kamaraju, V. 2011

TK 3144 H62 2001 Ryan, H.M. (ed.) High Voltage Engineering and 1
Testing, 2001

TK 153 A38 2004 Haddad A.et al Advances in High Voltage Engineering 1

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 Grading

• 30% Quizzes
• 30% Mid-term
• 40% Final Exam

Quizzes will be on Sunday.

Exams are close books and close notes. Mid-term is on Feb. 16th. The
final exam is on .

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 Examples of High Voltage Phenomena
Lightning Ionosphere

Picture Source:
www.iihr.uiowa.edu
Picture Source:
www.moonraker.com.au Flashover Arc
Corona

Picture Source:
www.corona-technology-course.com

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Examples of High Voltage Phenomena

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High Voltage Engineering

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 Couple Application Examples

Spark Plug Electron Beam Welding Power Transmission

Picture Source: ebwelding.com

Plasma Lamp

“Crafting the perfect shock”, Mark, W, Kroll, IEEE Spectrum, Dec. 2007

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 The Direct Danger: Current

“Crafting the perfect shock”, Mark, W, Kroll, IEEE Spectrum, Dec. 2007

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 What We will Learn in EE 468?

• High voltage phenomena and mechanisms

• High voltage generation and measurement methods
• Insulation material and break down mechanisms

Highlights: Hands on engineering

experience and practices on solving real
engineering problems

http://www.youtube.com/watch?v=romZnL8DWOc

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 Course Contents

• Chapter 1: High voltage generation and measurement

• Chapter 2: Electric and magnetic fields
• Chapter 3: Breakdown mechanisms
Breakdown in gases

Breakdown in liquids

Breakdown in solids
• Chapter 4: Corona and partial discharges
• Chapter 5: Surge generator and Tesla transformer

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 Introduction

Levels of high voltage:

World over the levels are classified as:

• LOW
• MEDIUM
• HIGH
• EXTRA and
• ULTRA HIGH Voltages

▪ However , the exact magnitude of these levels vary from country to country.
Hence this system of technical terms for the voltage levels is inappropriate .

▪ In most part of the world even 440 V is high voltage since it is dangerous for
the living being.

▪ Hence it would be more appropriate to always mention the level of voltage

being referred without any set nomenclature .

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 Introduction
VOLTAGE LEVELS
Consumer
• ac power frequency :
110 V, 220 V- single phase
440 V, 3.3 kV ,6.6 kV, 11 kV-three phase (3.3 & 6.6 kV are being phased out)

Generation : Three phase synchronous generators

440 V, 3.3 kV, 6.6 kV (small generators) , 11 kV (110 & 220 MW)
21.5 kV ( 500 MW), 33 kV (1000 MW)
[limitation due to machine insulation requirement]
Distribution :
Three phase 440 V, 3.3 kV, 6.6 kV, 11 kV, 33 kV, 66 kV
With the increase in power consumption density, the power distribution voltage levels
are at rise because the power handling capacity is proportional to the square of the
voltage level. (In Germany 440 V , 3.0 kV 6.0 kV, 10 kV, 30 kV, 60 kV)

ac Transmission : 110 kV, 132 kV, 220 kV, 380 - 400 kV, 500 kV, 765 - 800 kV, 1000 kV and
1150 kV exist. Work on 1500 kV is complete.
d.c. transmission : dc single pole and bipolar lines : ± 100 kV to ± 500 kV

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 Introduction
VOLTAGE LEVELS
Consumer
• ac power frequency :
110 V, 220 V- single phase
440 V, 3.3 kV ,6.6 kV, 11 kV-three phase (3.3 & 6.6 kV are being phased out)

Generation : Three phase synchronous generators

440 V, 3.3 kV, 6.6 kV (small generators) , 11 kV (110 & 220 MW)
21.5 kV ( 500 MW), 33 kV (1000 MW)
[limitation due to machine insulation requirement]
Distribution :
Three phase 440 V, 3.3 kV, 6.6 kV, 11 kV, 33 kV, 66 kV
With the increase in power consumption density, the power distribution voltage levels
are at rise because the power handling capacity is proportional to the square of the
voltage level. (In Germany 440 V , 3.0 kV 6.0 kV, 10 kV, 30 kV, 60 kV)

ac Transmission : 110 kV, 132 kV, 220 kV, 380 - 400 kV, 500 kV, 765 - 800 kV, 1000 kV and
1150 kV exist. Work on 1500 kV is complete.
d.c. transmission : dc single pole and bipolar lines : ± 100 kV to ± 500 kV

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 Introduction
Advance countries like US, Canada and Japan have their single phase ac power consumption level at 110 V .
Rest of the whole world consumes single phase ac power at 220 V .

The only advantage of 110 V single phase consumer voltage is that it is safer over 220 V. However, the
disadvantages are many.

Disadvantages :
• It requires double the magnitude of current to deliver the same amount of power as at 220 V

• Hence for the same magnitude of I^2*R losses to limit the conductor or the insulation temperature to 70°
C (for PVC) , the resistance of the distribution cable should be 4 times lower. Therefore, the cable cross-
section area has to be increased four folds.

• Four times more copper requirement, dumped in the building walls is an expensive venture.

• Due to higher magnitude of current, higher magnetic field in the buildings . Not good for health.

• With the installation of modern inexpensive protective devices (earth fault relays), 220 V is equally safe
as 110 V

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 Introduction

Rated maximum temperature of cables:

• It is important to understand the current and voltage carrying capacities of a conductor

separately. While the current carrying capability is determined by the conductivity of the
conductors, directly proportional to the area of conductor cross-section, the voltage bearing
capacity depends upon the level of insulation provided to the conductor .

• The current carrying capability in turn is determined by maximum permissible temperature of

the insulation or that of the conductor.

• The real power loss, I^2*R and the rate of cooling determine the temperature rise of the
conductor which should not be more than the maximum permissible temperature of the type
of insulation provided on the conductor .

• Hence, not only electrical but thermal and mechanical properties of insulation are important
in power system

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 Introduction
Electrical Insulation and Dielectrics

Gaseous Dielectrics:
• Atmospheric air is the cheapest and most widely used dielectric . Other gaseous dielectrics, used as
compressed gas at higher pressures than atmospheric in power system, are Nitrogen , Sulphur
hexafluoride SF6(an electro-negative gas) and it's mixtures with CO2 and N2 . SF6 is very widely
applied for Gas Insulated Systems (GIS), Circuit Breakers and gas filled installations i.e. sub-stations
and cables. It is being now applied for power transformers also.

Vacuum as Dielectric :
• Vacuum of the order of 10-5 Torr and lower provides an excellent electrical insulation. Vacuum
technology developed and applied for circuit breakers in the last three decades is phenomenon .

Liquid Dielectrics:
• Organic liquids, the mineral insulating oils and impregnating compounds, natural and synthetic, of
required physical, chemical and electrical properties are used very widely in transformers, capacitors,
cables and circuit breakers.

Solid Dielectrics:
• Very large in number .
• Most widely used are : XLPE, PVC, ceramics, glass, rubber, resins, reinforced plastics, polypropylene,
impregnated paper, wood, cotton, mica, pressboards, Bakelite, Perspex, Ebonite, Teflon, etc.
• Introduction of nano materials are in offing.

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