HVDC TRANSMISSION

Subject Code : EE722PE

Regulations : R16 - JNTUH

Class : IV Year B.Tech EEE I Semester

Department of Electrical and Electronics and Engineering

BHARAT INSTITUTE OF ENGINEERING AND TECHNOLOGY
Ibrahimpatnam - 501 510, Hyderabad.
 HVDC TRANSMISSION (EE722PE)

COURSE PLANNER

Course Title HVDC TRANSMISSION

Course Code EE722PE
Class B.Tech. IV Year I Semester EEE
Regulations JNTUH - R16
Lectures Tutorials /Bridge Practical Credits
Course Structure
3 1 - 4
Course Coordinator Mr.G.Kamalaker Reddy, Assistant Professor
Mr. G.Kamalaker Reddy, Assistant Professor
Team of Instructors
Mr. K .MurugaperumalAssistant Professor

I. COURSEOVERVIEW:

This subject deals with importance of HCDC transmission, analysis of HVDC converts, Harmonics and
filters, reactive power control and power factor improvement of the system.

This course provides

 The foundations of high voltageDC transmission in the Power systems.

 Topics include basics of converters, system control and power flow analysis, harmonics and filters
II. PREREQUISITE(S)

Level Credits Periods/ Week Prerequisites

Power Systems

UG 4 4 Power Electronics

III. COURSEOBJECTIVES:

At the end of the course, the students will be able to:

 To compare EHV AC and HVDC systems and various Types of DC links

 To analyze Graetz circuit with different mode of operations
 To control HVDC systems through various methods of AC/DC power flow study
 To describe various protection methods for HVDC systems and Harmonics reduce filter design.
IV. COURSEOUTCOMES:

After completing this course the student must demonstrate the knowledge and ability to:

Knowledge Level
S. No. Course Outcomes (CO)
(Blooms Level)
CO1 Distinguish between EHV AC and HVDC systemsand various types L2: UNDERSTAND
of DC links.
Design the Graetz circuit with different mode of operations
CO2 L4: ANALYZE
CO3 Generalize the importance of HVDC converters, AC/DC Power L2: UNDERSTAND
flow and its reactive power control techniques
CO4 Compute various converter’s faults and its protections L3: APPLY

CO5 Design the harmonics reduction filters for HVDC transmission L4: ANALYZE

V. HOW PROGRAM OUTCOMES AREASSESSED:

Proficiency
Program Outcomes (PO) Level
assessed by

PO1 Engineering knowledge: Apply the knowledge of

mathematics, science, engineeringfundamentals, and an
engineering specialization to the solution of complex 3 Assignments
engineering problems related to Electrical and Electronics
Engineering.

PO2 Problem analysis: Identify, formulate, review research

literature, and analyze complexengineering problems
related Electrical and Electronics Engineering and Open ended
3
reaching substantiated conclusions using first principles experiments /
of mathematics, natural sciences, and engineering
sciences.

PO3 Design/development of solutions: Design solutions for

complex engineering problems related Electrical and
Electronics Engineering anddesign system components or
2 Assignments
processes that meet the specified needs with appropriate
consideration for the public health and safety, and the
cultural, societal, and environmental considerations.

PO4 Conduct investigations of complex problems: Use

research-based knowledge and researchmethods including ---- ------
design of experiments, analysis and interpretation of data,
 Proficiency
Program Outcomes (PO) Level
assessed by

and synthesis of the information to provide valid

conclusions.

PO5 Modern tool usage: Create, select, and apply appropriate

techniques, resources, and modernengineering and IT
tools including prediction and modeling to complex ---- ------
engineering activities with an understanding of the
limitations.

PO6 The engineer and society: Apply reasoning informed by

the contextual knowledge to assesssocietal, health, safety,
Case study
legal and cultural issues and the consequent 1
Analysis
responsibilities relevant to the Electrical and Electronics
Engineering professional engineering practice.

PO7 Environment and sustainability: Understand the impact of

the Electrical and Electronics Engineering professional
engineering solutionsin societal and environmental ---- --------
contexts, and demonstrate the knowledge of, and need for
sustainable development.

PO8 Ethics: Apply ethical principles and commit to professional

ethics and responsibilities and norms ofthe engineering ---- -------
practice.

PO9 Individual and team work: Function effectively as an

individual, and as a member or leader indiverse teams, and ---- -------
in multidisciplinary settings.

PO10 Communication: Communicate effectively on complex

engineering activities with the engineeringcommunity and
with society at large, such as, being able to comprehend
---- -------
and write effective reports and design documentation,
make effective presentations, and give and receive clear
instructions.

PO11 Project management and finance: Demonstrate

knowledge and understanding of theengineering and
management principles and apply these to one’s own ---- -------
work, as a member and leader in a team, to manage
projects and in multidisciplinary environments.
 Proficiency
Program Outcomes (PO) Level
assessed by

PO12 Life-long learning: Recognize the need for, and have the
preparation and ability to engage inindependent and life-
1 Competitive
long learning in the broadest context of technological
change. Examinations

1:Slight(Low) 2:Moderate(Medium) 3:Substantial(High) - :None

VI. HOW PROGRAM SPECIFIC OUTCOMES AREASSESSED:

Proficiency
Program Specific Outcomes (PSO) Level
assessed by

PSO1 Talented to analyze, design, and implement electrical & electronics

Lectures/
systems and deal with the rapid pace of industrial innovations and
PSO1 2 Assignments/
developments.
NPTEL

PSO2 Skillful to use application and control techniques for research and
advanced studies in Electrical & Electronics Engineering domain.
2 Mini Projects

/ Simulation

1: Slight (Low) 2: Moderate (Medium) - : None

3: Substantial (High)

VII. SYLLABUS:

UNIT – I

Basic Concepts: Necessity of HVDC systems, Economics and Terminal equipment of HVDC transmission
systems, Types of HVDC Links, Apparatus required for HVDC Systems, Comparison of AC and DC
Transmission, Application of DC Transmission System, Planning and Modern trends in D.C.
Transmission.
 Analysis of HVDC Converters: Choice of Converter Configuration, Analysis of Graetz circuit,
Characteristics of 6 Pulse and 12 Pulse converters, Cases of two 3 phase converters in Y/Y mode – their
performance.

UNIT – II

Converter and HVDC System Control: Principle of DC Link Control, Converters Control Characteristics,
Firing angle control, Current and extinction angle control, Effect of source inductance on the system,
Starting and stopping of DC link, Power Control.

Reactive Power Control In HVDC: Introduction, Reactive Power Requirements in steady state, sources
of reactive power- Static VAR Compensators, Reactive power control during transients.

UNIT – III

Power Flow Analysis in AC/DC Systems: Modeling of DC Links, DC Network, DC Converter, Controller
Equations, Solution of DC load flow, P.U. System for DC quantities, solution of AC-DC Power flow-
Simultaneous method-Sequential method.

UNIT – IV

Converter Faults and Protection: Converter faults, protection against over current and over voltage in
converter station, surge arresters, smoothing reactors, DC breakers, Audible noise, space charge field,
corona effects on DC lines, Radio interference.

UNIT – V

Harmonics: Generation of Harmonics, Characteristics harmonics, calculation of AC Harmonics, Non-

Characteristics harmonics, adverse effects of harmonics, Calculation of voltage and Current harmonics,
Effect of Pulse number on harmonics Filters: Types of AC filters, Design of Single tuned filters –Design
of High pass filters.

TEXT BOOKS:

1. “K. R. Padiyar”, HVDC Power Transmission Systems: Technology and system Interactions, New Age
International (P) Limited, and Publishers, 1990.

2. “S K Kamakshaiah, V Kamaraju”, HVDC Transmission, TMH Publishers, 2011

 3. “S. Rao”, EHVAC and HVDC Transmission Engineering and Practice, Khanna publications, 3rd Edition
1999.

REFERENCE BOOKS:

1. “Jos Arrillaga”, HVDC Transmission, The institution of electrical engineers, IEE power & energy series
29, 2nd edition 1998.

2. “E. W. Kimbark”, Direct Current Transmission, John Wiley and Sons, volume 1, 1971.

3. “E. Uhlmann”, Power Transmission by Direct Current, B. S. Publications, 2009

NPTEL Video Lectures

1.https://nptel.ac.in/courses/108104013/

2.https://nptel.ac.in/courses/108104013/1

3.https://nptel.ac.in/courses/108104013/2

4.https://nptel.ac.in/courses/108104013/3

5.https://nptel.ac.in/courses/108104013/4

6. https://nptel.ac.in/courses/108104013/5

7. https://nptel.ac.in/courses/108104013/6

8. https://nptel.ac.in/courses/108104013/7

9.https://nptel.ac.in/courses/108104013/8

10.https://nptel.ac.in/courses/108104013/9

VIII. COURSEPLAN:

At the end of the course, the students are able to achieve the following course learning outcomes:

Topics to be covered Teaching References

Lecture no

Course Learning Outcomes Methodologies

Unit no
week

1 1 Necessity of HVDC systems chalk & talk T1, R2

Able to understand the
2. Economics and Terminal equipment EHV and DC transmission chalk & talk T1, R2
of HVDC transmission systems, merits and drawbacks
3. Types of HVDC Links, Apparatus chalk & talk T1, R2
required for HVDC Systems,
4. Comparison of AC and DC chalk & talk T1, R2
Transmission, Application of HVDC
2 Planning and Modern
Transmission System trends in D.C. chalk & talk T1, R2
5.
Transmission.
6. Choice of Converter Configuration chalk & talk T1, R2

Analysis of Graetz circuit, Able to design basic chalk & talk T1, R2
7.
Characteristics of 6 Pulse and 12 Graets circuit and
1 Characteristics of 6 Pulse and 12 PPT T1, R2
8. Pulse converters analysing of its
Pulse converters
9. 3 Two 3 phase converters in Y/Y mode performance chalk & talk T1, R2

10. Y/Y mode performance chalk & talk T1, R2

MOCK TEST I

11. 2 Principle of DC Link Control chalk & talk T1, R2

12. Converters Control Characteristics, Able to understand about chalk & talk T1, R2
different control
13. 4 Firing angle control techniques of HVDC chalk & talk T1,T2
system

14. Current and extinction angle control chalk & talk T1,T2

Effect of source inductance on the chalk & talk T1,T2

system
15. Starting and stopping of DC link and chalk & talk T1,T2
Able to understand about
Power Control
16. DC link characteristics
5 Introduction about Reactive Power chalk & talk T1,T2
Requirements
17.
18. sources of reactive power PPT T1,T2

19. Static VAR Compensators chalk & talk T1,T2

Able to understand about
20. Reactive power control during VAR compensators chalk & talk T1,T2
transients

21. 6 3 Modelling of DC Links chalk & talk T1,T2

22. Modelling of DC Links chalk & talk T1,T2

Able to analysis the
23. DC Network, DC Converter chalk & talk T1,T2
modelling of DC links
24. Controller Equations and load flows chalk & talk T1,T2

25. 7 Solution of DC load flow, chalk & talk T1,T2

26. Solution of DC load flow, PPT NTPEL

P.U. System for DC quantities chalk & talk T1,T2
solution of AC-DC Power flow Able to develop the chalk & talk T1,T2
27.
Simultaneous method
28.
 8 Solution of AC-DC Power flow - solution for AC-DC chalk & talk T1,T2
Sequential method. power flow
29.
30. Comparison between Simultaneous chalk & talk T1,T2
method and Sequential method.
31. 4 Intro about Converter faults, Able to identify the chalk
PPT & talk T1,T2
converter faults
32. Converter faults, chalk & talk T1,T2

33. 9 protection against over current and chalk & talk T1,T3
over voltage in converter station
protection against over current and chalk & talk T1,T3
over voltage in converter station
34.
35. surge arresters, smoothing reactors chalk & talk T1,T3
Able to understand the
smoothing reactors, DC breakers HVDC link protection chalk & talk T1,T3
36.
methods
37. 10 Audible noise, space charge field chalk & talk T1,T3

38. corona effects on DC lines chalk & talk T1,T3

MOCK TEST II

39. Radio interference chalk & talk T1,T3

40. 5 Intro Harmonics chalk & talk

PPT NTPEL

41. 11 Generation of Harmonics chalk & talk T1,R2

42. Characteristics harmonics chalk & talk T1,R2

calculation of AC Harmonics chalk & talk T1,R2
calculation of AC Harmonics Able to understand chalk & talk T1,R2
43.
different types of
45. 12 Non- Characteristics harmonics chalk & talk T1,R2
44. Harmonics and its
46. adverse effects of harmonics chalk & talk T1,R2
behaviours.
Calculation of voltage and Current chalk & talk T1,R2
harmonics
47.
48. Calculation of voltage and Current chalk & talk T1,R2
harmonics
49. 13 Effect of Pulse number on chalk & talk T1,R2
harmonics

50. Filters: Types of AC filters chalk & talk T1,R2

51. Design of Single tuned filters chalk & talk T1,R2

Design of Single tuned filters Able to design different chalk & talk T1,R2
52.
14 Design of High passes filters. filters circuits for HVDC chalk & talk T1,R2
53. transmission
54. Design of High passes filters. chalk & talk T1,R2
55. HVDC transmission advancements Case study -
analysis
 IX. MAPPING COURSE OUTCOMES LEADING TO THE ACHIEVEMENT OF PROGRAM OUTCOMES AND
PROGRAM SPECIFICOUTCOMES:
Program
Specific
Program Outcomes (PO)
Course Outcomes

Outcomes
(PSO)

PO10

PO11

PO12

PSO1

PSO2
PO1

PO2

PO3

PO4

PO5

PO6

PO7

PO8

PO9
CO1 3 3 2 1 1 2 2

CO2 3 3 2 1 1 2 2

CO3 3 3 2 1 1 2 2

CO4 3 3 2 1 1 2 2

CO5 3 3 2 1 1 2 2

AVG 3 3 2 1 1 2 2

3: Substantial
2: Moderate - : None
1: Slight (Low) High)
(Medium)

X. QUESTION BANK (JNTUH)

Blooms Taxonomy Course

S. No Question Level Outcome

UNIT - I

SHORT ANSWER TYPE QUESTIONS

1 List out the applications of HVDC? Understand 1

2 What are the types of transmission system? Analyze 1

State the comparison of AC & DC transmission

3 Remember 1
system?
4 State the disadvantage in dc transmission? Understand 1

5 State the advantages in DC transmission? Remember 1

6 What are the types of DC link? Understand 1

7 Name the HVDC transmission in india? Understand 1

What are the limitations of EHVAC

8 Remember 1
transmission?

9 What are the types of dc links? Understand 1

Draw the cost vs distance curve of ac and dc

10 Understand 1
transmission?

11 Define pulse number? Remember 1

12 Draw the diagram graetz bridge circuit Analyze 1

Write the equation of ac current and dc voltage

13 Analyze 1
harmonics

14 What is choice of converter configuration? Analyze 1

15 Define peak inverse voltage? Remember 1

Draw the schematic diagram of three & two

16 Understand 1
valve conduction mode

Define twelve pulse converter with schematic

17 Remember 1
diagram

What is meant by neglecting overlap in gratez in

18 Remember 1
bridge circuit

19 What is commutation voltage of valves? Understand 1

What are the assumptions made to simplify the

20 Remember 1
analysis of Gratez circuit?

LONG ANSWER QUESTIONS

What are the different applications of dc

1 Analyze 1
transmission system? Explain them in detail?

With neat sketches explain the different kinds

2 Analyze 1
of dc link available?
 Explain the comparison of AC and DC
3 Understand 1
transmission in detail

Explain in detail about the planning of HVDC

4 Analyze 1
transmission?

Explain the technological development of

5 Analyze 1
modern trends in dc transmission

Explain the major components of HVDC

6 Apply 1
transmission in converter station unit?

State the advantages and disadvantages of dc

7 transmission system with following economics, 1
reliability, and performance Understand

Draw a typical HVDC layout and explain their

8 Analyze 1
basic components?

Explain the modern trends in dc transmission? Apply 1

9

Explain the application of HVDC c transmission

Analyze 1
system?
10

Draw the schematic circuit diagram of a 6 pulse

11 gratez circuit and explain its principle of Understand 1
operation.

Explain the individual characteristics of a

12 Understand 1
rectifier and an inverter with sketch

Derive the expression for input power, output

power and power factor of 12- pulse bridge
13 Analyze 1
converter with delay angle α. Assume there is
no overlap.

Explain the effect of overlap angle on the

14 Analyze 1
performance of converter circuit

Explain the choice of converter configuration

15 Analyze 1
for any pulse number

Explain the analysis of 12 pulse converter with

16 Analyze 1
bridge rectifier
 Give the typical converter transformer rating for
17 Analyze 1
a HVDC transmission system?

Explain the term angle of advance and its

18 Analyze 1
significance in inverter control

What are the different types of modes of

19 Understand 1
operation of rectifier?

Write down the average dc voltage of Graetz

20 Understand 1
circuit without overlap?

21 Compare EHVAC and HVDC transmission? Understand 1

22 Explain the limitation of EHVAC system? Understand 1

23 Explain the different types of HVDC link? Understand 1

Explain the application of HVDC transmission

24 Understand 1
system?

Explain the planning for HVDC transmission

25 Remember 1
system?

26 Explain the modern trends in dc transmission? Evaluate 1

Draw the variation of voltage along the

transmission line during different
27 Apply 1
loading condition?

What are the different applications of dc

28 transmission system? Explain them in Apply 1
detail?

Explain in detail about the planning of HVDC

29 Apply 1
Transmission?

State the advantages and disadvantages of dc

transmission system with
30 Apply 1
following economics, reliability, and
performance

Explain with the help of neat diagram and wave

forms, the operation of 6-pulse bridge
converter with delay angle a and overlap angle
 u. derive the expression

31 for its dc output voltage Remember 1

Show the rating of the valve used in gratez

32 circuit is 2.094Pd where Pd is dc Understand 1
power transmitted.

What are the different types of modes of

33 Remember 1
operation of rectifier?

Write down the converter bridge

34 Understand 1
characteristics?

Derive the expression for input power, output

power and power factor of 6-
35 Apply 1
pulse bridge converter with delay angle α.
Assume there is no overlap.

Sketch the output dc voltage waveform and

voltage across any one valve for 6- pulse bridge
converter for the following two cases,

(i) Delay angle α=30 degree and overlap

36 Remember 1
angle u=5 degree.

(ii) angle of advance β=30 degree and

overlap angle u=5 degree

37 Explain in detail the principle of DC Link control. Apply 1

Explain firing angle control & current and

38 Remember 1
extinction angle control

Sketch the output dc voltage waveform and

39 voltage across any one valve for Apply 1
12-pulse bridge

Give the typical converter transformer rating for

40 Apply 1
aHVDC transmission system?
 UNIT - II

SHORT ANSWER TYPE QUESTIONS

1 What will be the current regulation in inverter side? Understand 2

2 Define firing angle control. Understand 2

3 What is un compounded inverter? Understand 2

Draw the characteristics curve for inverter

4 Analyze 2
compounding?

5 Write down the converter bridge characteristics? Analyze 2

6 Explain overlap angle and extinction angle. Analyze 2

Discuss in detail the effect of source inductance on

7 Analyze 2
hvdc system

Explain the individual characteristics of a rectifier and

8 Analyze 2
an inverter with sketches.

9 Explain current and extinction angle control. Analyze 2

Draw and explain the inverter and rectifier

10 compounding characteristics with constant voltage Apply 2
and current curve.

LONG ANSWER QUESTIONS

Explain firing angle control & current and extinction

1 Analyze 2
angle control

2 Explain overlap angle and extinction angle. Remember 2

Define the term angle of advance and its significance

3 Remember 2
in inverter control

Explain the individual characteristics of a rectifier and

4 Analyze 2
an inverter with sketches

Discuss in detail about the transformer tap changer

5 Analyze 2
with its types

6 Discuss in detail about the converter control Analyze 2

 characteristics of hvdc system

7 Discuss in detail the principle of DC Link control. Analyze 2

8 Explain the system control hierarchy Analyze 2

Explain the un compounded inverter with neat

9 Understand 2
sketches

Why the delay angle and extinction angles are to be

10 Understand 2
maintained to minimum value

ANALYTICAL QUESTIONS

1 Explain in detail the principle of DC Link control Understand 2

Explain the term angle of advance and its significance

2 Understand 2
in inverter control

What are the different types of modes of operation of

3 Understand 2
rectifier?

Explain firing angle control & current and extinction

Understand 2
4 angle control

5 Explain the system control hierarchy Analyze 2

6 Explain overlap angle and extinction angle. Apply 2

7 What will be the current regulation in inverter side Apply 2

Why the delay angle and extinction angles are to be

8 maintained to minimum Understand 2
value

Explain the individual characteristics of a rectifier and

9 an inverter with Apply 2
sketches

Explain in detail about the transformer tap changer

10 Apply 2
with its types

UNIT - III
 SHORT ANSWER TYPE QUESTIONS

Write the different types of AC/DC power

1 Analyze 3
flow

2 What is unified method of DC power flow? Understand 3

3 What is sequential method of DC power flow? Remember 3

What are the advantages of variable

4 elimination method over extended variable Apply 3
method?

5 Draw the DC system model Remember 3

Draw the norton’s equivalent circuit for a

6 Remember 3
converter

What are the additional constraints needed to

7 Remember 3
include for ac-dc power flow

8 List some essentials of power flow analysis Evaluate 3

Compare sequential and simultaneous

9 Remember 3
methods of ac-dc power flow.

What are the major steps in the power flow

10 Remember 3
analysis of MTDC-AC Systems

LONG ANSWER QUESTIONS

Discuss the various sources of reactive power

1 Understand 3
for HVDC converters.

What is the reactive power requirement in

2 Remember 3
steady state

3 Discuss conventional control strategies Evaluate 3

4 Discuss alternate control strategies Evaluate 3

Write the operation of synchronous

5 Analyze 3
condensers.

Explain extended variable method of DC

6 Analyze 3
power flow
 Explain the variable elimination method of DC
7 Evaluate 3
power flow

Explain the sequential method of DC power

8 Evaluate 3
flow. Draw the necessary flow chart.

Explain about per unit system for DC

9 Evaluate 3
quantities

Compare sequential and unified methods of

10 Apply 3
DC power flow.

UNIT - IV

SHORT ANSWER TYPE QUESTIONS

What are the additional constraints needed to 4

1 Remember
include for ac-dc power flow?

2 List some essentials of power flow analysis Evaluate 4

Compare sequential and simultaneous 4

3 Remember
methods of ac-dc power flow.

What are the major steps in the power flow 4

4 Remember
analysis of MTDC-AC Systems

5 Define AC filter? Remember 4

6 Define DC Filter? Understand 4

What are the components present in AC & DC 4

7 Remember
filter?

8 What are the types of AC filters & Dc? Apply 4

9 Define single tuned filter? Remember 4

10 How will protect the filter? Remember 4

LONG ANSWER QUESTIONS

Discuss the various sources of active power 4

1 Understand
for HVDC converters

2 What is the reactive power requirement in Apply 4

 steady state

Explain extended variable method of DC 4

3 Remember
power flow

Explain the variable elimination method of DC 4

4 Remember
power flow

Explain the sequential method of DC power 4

flow. Draw the necessary flow
5 Remember
chart

Explain about per unit system for DC 4

6 Remember
quantities

Compare sequential and unified methods of 4

7 Apply
DC power flow

8 Explain unified method of DC power flow Remember 4

What are the additional constraints needed to 4

9 Understand
include for ac-dc power flow?

Compare sequential and simultaneous 4

10 Apply
methods of ac-dc power flow

State the various sources of harmonics 4

generation in HVDC-VSC systems and mention
11 Apply
the adverse effects caused by these
harmonics

With neat sketches, explain how a converter 4

transformer is responsible for generation of
12 Evaluate
harmonics and suggest various methods for
minimising them

Define telephone interference Factor and 4

13 Remember
Explain how it varies with harmonic order.

What are the non-characteristics of 4

14 harmonics in HVDC system? How are they Evaluate
generated?

What are other methods of eliminating 4

15 Apply
harmonics with HVDC system
 Explain the need to employ filter circuit in 4
HVDC systems. Derive an Expression for
minimum cost of tuned AC filters used in 4
16 Apply
HVDC systems.

Derive an equation for harmonic voltage and 4

17 current for single tuned filter and discuss the Analyse
influence of network admittance

Give a detailed account of design aspects of 4

following filters
Analyse
18 (a) Single tuned filter (b)Double tuned filter 4

What are the other methods of eliminating or 4

suppressing harmonics with HVDC system?
19 Analyze
Give a comparison using passive filter
network

UNIT - V

SHORT ANSWER TYPE QUESTIONS

1 Define Harmonic Analyze 5

2 How harmonics are generated? Understand 5

Mention the various sources of harmonic 5

3 Remember
generation in HVDC system

What are other methods of eliminating 5

4 Remember
harmonics with HVDC system

Write the different types of AC/DC power 5

5 Analyze
flow

6 What is unified method of DC power flow? Understand 5

7 What is sequential method of DC power flow? Remember 5

What are the advantages of variable 5

8 elimination method over extended variable Apply
method?

9 Draw the DC system model Remember 5

 Draw the norton’s equivalent circuit for a 5
10 Understand
converter

LONG ANSWER QUESTIONS

1 Explain unified method of DC power flow Analyze 5

What are the additional constraints needed to 5

2 Analyze
include for ac-dc power flow?

Compare sequential and simultaneous 5

3 Apply
methods of ac-dc power flow

Write a short note on the following: 5

4 (a) Harmonic distortion Apply 5

(b) telephone Influence factor 5

Mention the various sources of harmonic 5

5 generation in HVDC systems and suggest Analyze
methods to eliminate them

Define telephone interference Factor and 5

6 Analyze
Explain how it varies with harmonic order.

What are the order of harmonics present on 5

7 Analyze
the AC side of the VSC converter DC systems

What are the filter configurations that are 5

8 employed for HVDC Converter station? Give Understand
design aspect of one such filter

Derive an equation for harmonic voltage and 5

9 current for single tuned filter and discuss the Evaluate
influence of network admittance

Give a detailed account of design aspects of 5

following filters

10 (a) Single tuned filter Understand 5

(b) Double tuned filter 5

What are the different types of filters used on 5

11 the AC side of an HVDC system? How are they Apply
located and arranged?
OBJECTIVE QUESTIONS:

UNIT-1

1) Which among these HVDC projects are commissioned in India?

a.Rihand – Delhi HVDC

b.Vindhyachal Back to Back only
c.Chandrapur only
d.All of these
e. None of these

ans:d

2) At what location are the shunt capacitors installed for voltages above 33 kV and above?

a. Are located near the motors

b.Are installed in distribution substations
c. Both (A) and (B)
d. None of these

ans:b

3) What is meant by Creepage Distance?

a. Shortest distance between two conducting parts along a stretched string.

b. Shortest distance between two conducting parts along the surface of the insulating material.
c. Distance between ground and the highest earthed point on the equipment.
d. All of these

ans:b

4) Which among these is a part of HVDC link?

a. Two earth electrodes

b. Converter valves
 c. Bipolar DC line
d.All of these
e. None of these

ans:d

5) At what level is the load shedding carried out?

a. Distribution level
b. Transmission level
c. Both (A) and (B)
d. Depending upon the load

ans:a

UNIT-2

1) Which place is the ‘Regional load dispatch centre’ for the western region in the national grid?

a. Mumbai
b. Ahmadabad
c. Bhopal
d. Nagpur

ans:a

2) What type of insulation is preferred for DC smoothing Reactors?

a. Air
b. Oil
c. Paper
d. Varnish

ans:b

3) At what condition does the corona start, if Es is the electrical stress and Ecr is the critical voltage?

a.Es>Ecr
b.Es = Ecr
c.Es<Ecr
d.Es<<Ecr
ans:a

4) Which method of voltage control is applied for long line AC transmissions?

a. Switching by shunt capacitors

b. Tap changing transformers
c.Switching by shunt reactors
d. Static Var sources

ans: c

5) For what voltage is Twin conductor bundle used in India?

a. 220 kV
b. 500 kV
c. 750 kV
d. 330 kV

ans:b

UNIT 3

1. Which type of dc link, all conductors

1. have negative polarity

(a) Homopolar (b) Monopolar(c) Bipolar (d)None

ans:a

2. When two power systems are connected

2. through ac ties, the automatic generation
control of both systems have to be coordinated using

(a) Line current &voltage signals (b) Line power & voltage signals

(c) Line power & frequency signals (d) Line current & frequency signals

ans :c

3. Which factor must be considered by system planner for expansion of dc alternative

in transmission

(a) Cost (b)Technical performance (c) Reliability (d)All

ans:d

4. The break even distance can vary in the range for over head lines

(a)300km (b)500km (c) 100km (d) 1000km

ans:b

5. The following is the application of hvdc transmission (a)Small distance bulk

power transmission (b) Medium bulk power transmission

(c)Long distance bulkpower transmission (d)None

ans:c

UNIT 4

1. HVDC transmission commercially began in the year

(a)1950 (b) 1954 (c) 1970 (d)1935

ans:b

2. Modern HVDC systems are all

(a) 3-pulse converters (b) 6-pulse converters

(c) 24-pulse converters (d) 12-pulse converters

ans:b

3. The break even distance is the distance beyond which

(a) DC transmissionis economical (b) AC transmission is economical

(c) Cost of the both systems are same (d) Both(b)and(c)

ans:a

4. The initial HVDC valves were

(a) IGATS (b) Thyristors

(c) Mercury arc valves (d) None of the above

ans:c

5. Thyristor valves came into operation in the year

(a)1950 (b)1954 (c)1972 (d)2000

ans :b

UNIT-5

Fill in the blanks

1. The synchronous condenser which is operated at

2. The first HVDC scheme in India________________________
3. HVDC-VSC scheme employs in ___________
4. In 12-pulse converter transformers are connected------------------

5. The main advantage of HVDC over HVAC _______

Answers: 1. Lagging power factor 2. Delhi-Rihand 500kv system 3. Light or optically triggered 4.
one Star/Star and otherStar/Delta 5. Transmission loss less

XI. WEBSITES:

https://www.edx.org/course/HVDC transmission

https://www.edx.org/micromasters/EHV vs HVDC

XII. EXPERT DETAILS: NA

XIII. JOURNALS:

INTERNATIONAL

1. International Journal of smart grid transmission (IJSGT)

2. International Journal of Power system transmission (IJPST)
 NATIONAL

1. Journal of power system and Applications

2. Journal of energy Research and Development

XIV. LIST OF TOPICS FOR STUDENT SEMINARS:

1. Advanced dc link protections

2. Comparison between EHV and UHV
3. HVDC control and operations.

XV. CASE STUDIES / SMALL PROJECTS:

1. Preparing layout for HVDC transmission station

2. Develop the step by step procedure for the HVDC transmission.

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