JNTU Kakinada B-Tech 4-2 FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS R13 April 2018 Question Paper

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) List and explain briefly important controllable parameters that are considered
for power flow control.
[4]
b) Explain basic principle of voltage source converter. [4]
c) Explain necessity of VAR compensation in transmission system. [3]
d) Explain different losses that are encountered with FC ? TCR arrangement. [4]
e) List merits of Hybrid compensator. [3]
f) Explain main objectives and usefulness of UPFC in power industry. [4]

PART ?B (3×16 = 48 Marks)2. a) Name and explain different types of stability issues that limit transmission
capability.
[8]
b) What are FACT controllers and explain different categories of FACT
controllers
[8]

3.
Explain the operation of three phase full wave bridge type voltage source
converter with a neat circuit along with the necessary waveforms
[16]

4. a) Explain prevention of voltage stability with the help of end of line voltage
support.
[8]
b) Explain basic operation of Thyristor Switched Capacitor with necessary
waveforms.
[8]

5. a) Explain with a neat block diagram general control scheme of Static Var
Compensator (SVC).
[8]
b) What is transient stability? How attainable enhancement of transient stability
can be done by SVC and STATCOM?
[8]

6. a) Explain with a neat functional diagram, implementation of Var Reserve (operating point) control for damping of Power oscillations in the system.
[8]
b) Explain about basic GTO-controlled series capacitor with principle of operation
and necessary waveforms.
[8]

7. a) Give a comparison between UPFC to IPFC. [8]
b) Explain principle of operation of IPFC with neat diagram. [8]

Code No: RT42023C
Set No. 1
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) List and explain briefly important controllable parameters that are considered
for power flow control.
[4]
b) Explain basic principle of voltage source converter. [4]
c) Explain necessity of VAR compensation in transmission system. [3]
d) Explain different losses that are encountered with FC ? TCR arrangement. [4]
e) List merits of Hybrid compensator. [3]
f) Explain main objectives and usefulness of UPFC in power industry. [4]

PART ?B (3×16 = 48 Marks)2. a) Name and explain different types of stability issues that limit transmission
capability.
[8]
b) What are FACT controllers and explain different categories of FACT
controllers
[8]

3.
Explain the operation of three phase full wave bridge type voltage source
converter with a neat circuit along with the necessary waveforms
[16]

4. a) Explain prevention of voltage stability with the help of end of line voltage
support.
[8]
b) Explain basic operation of Thyristor Switched Capacitor with necessary
waveforms.
[8]

5. a) Explain with a neat block diagram general control scheme of Static Var
Compensator (SVC).
[8]
b) What is transient stability? How attainable enhancement of transient stability
can be done by SVC and STATCOM?
[8]

6. a) Explain with a neat functional diagram, implementation of Var Reserve (operating point) control for damping of Power oscillations in the system.
[8]
b) Explain about basic GTO-controlled series capacitor with principle of operation
and necessary waveforms.
[8]

7. a) Give a comparison between UPFC to IPFC. [8]
b) Explain principle of operation of IPFC with neat diagram. [8]

Code No: RT42023C
Set No. 1
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) Explain need of transmission interconnection. [3]
b) Distinguish between current source and voltage source converters. [4]
c) Explain need of dynamic voltage control in a transmission system. [4]
d) List different methods of controllable VAR generation [3]
e) Explain important features of GTO thyrister controlled series capacitor. [4]
f) Explain the importance of Interline power flow controller(IPFC) [4]

PART ?B (3×16 = 48 Marks)2. a) Explain different dynamic stability considerations that were taken for a
transmission interconnection.
[8]
b) Explain relative importance of different types of FACTS controllers. [8]

3. a) Explain reasons for possessing harmonics in a single phase bridge circuit and
how it can be nullified.
[8]
b) Explain operation of three phase full wave diode converter (neglecting
commutation angle) with a neat circuit and necessary waveforms.
[8]

4. a) Explain the operation of two-machine Power system with an ideal midpoint
reactive compensator with an equivalent circuit and necessary phasor diagram.
[8]
b) Explain in detail about power oscillation damping and why it is considered as
dynamic event.
[8]

5. a) Explain TSC ? TCR type static var generator with a neat functional control
Scheme.
[8]
b) Explain with reasons, why static compensator is not used as a perfect terminal
voltage regulator but allowed to vary in proportion with compensating current.
[8]

6. a) Explain main elements of the overall static compensator control system. [8]
b) Explain concept of voltage stability and improvement of transient stability. [8]

7. a) Discuss the features of UPFC. [6]
b) Explain the basic operating principles and characteristics of Interline Power
Flow Controller (IPFC).
[10]

Code No: RT42023C
Set No. 2
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) List and explain briefly important controllable parameters that are considered
for power flow control.
[4]
b) Explain basic principle of voltage source converter. [4]
c) Explain necessity of VAR compensation in transmission system. [3]
d) Explain different losses that are encountered with FC ? TCR arrangement. [4]
e) List merits of Hybrid compensator. [3]
f) Explain main objectives and usefulness of UPFC in power industry. [4]

PART ?B (3×16 = 48 Marks)2. a) Name and explain different types of stability issues that limit transmission
capability.
[8]
b) What are FACT controllers and explain different categories of FACT
controllers
[8]

3.
Explain the operation of three phase full wave bridge type voltage source
converter with a neat circuit along with the necessary waveforms
[16]

4. a) Explain prevention of voltage stability with the help of end of line voltage
support.
[8]
b) Explain basic operation of Thyristor Switched Capacitor with necessary
waveforms.
[8]

5. a) Explain with a neat block diagram general control scheme of Static Var
Compensator (SVC).
[8]
b) What is transient stability? How attainable enhancement of transient stability
can be done by SVC and STATCOM?
[8]

6. a) Explain with a neat functional diagram, implementation of Var Reserve (operating point) control for damping of Power oscillations in the system.
[8]
b) Explain about basic GTO-controlled series capacitor with principle of operation
and necessary waveforms.
[8]

7. a) Give a comparison between UPFC to IPFC. [8]
b) Explain principle of operation of IPFC with neat diagram. [8]

Code No: RT42023C
Set No. 1
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) Explain need of transmission interconnection. [3]
b) Distinguish between current source and voltage source converters. [4]
c) Explain need of dynamic voltage control in a transmission system. [4]
d) List different methods of controllable VAR generation [3]
e) Explain important features of GTO thyrister controlled series capacitor. [4]
f) Explain the importance of Interline power flow controller(IPFC) [4]

PART ?B (3×16 = 48 Marks)2. a) Explain different dynamic stability considerations that were taken for a
transmission interconnection.
[8]
b) Explain relative importance of different types of FACTS controllers. [8]

3. a) Explain reasons for possessing harmonics in a single phase bridge circuit and
how it can be nullified.
[8]
b) Explain operation of three phase full wave diode converter (neglecting
commutation angle) with a neat circuit and necessary waveforms.
[8]

4. a) Explain the operation of two-machine Power system with an ideal midpoint
reactive compensator with an equivalent circuit and necessary phasor diagram.
[8]
b) Explain in detail about power oscillation damping and why it is considered as
dynamic event.
[8]

5. a) Explain TSC ? TCR type static var generator with a neat functional control
Scheme.
[8]
b) Explain with reasons, why static compensator is not used as a perfect terminal
voltage regulator but allowed to vary in proportion with compensating current.
[8]

6. a) Explain main elements of the overall static compensator control system. [8]
b) Explain concept of voltage stability and improvement of transient stability. [8]

7. a) Discuss the features of UPFC. [6]
b) Explain the basic operating principles and characteristics of Interline Power
Flow Controller (IPFC).
[10]

Code No: RT42023C
Set No. 2
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) Explain concept of power flow in ac system and explain difference when one of
the parallel path is replaced with HVDC transmission.
[4]
b) Explain reasons for absence of neutral connection in a full wave circuit. [4]
c) List functional requirements of reactive shunt compensators. [3]
d) List major functions pf TSC ?TCR type Var generator. [4]
e) Explain basic idea behind series capacitive compensation. [3]
f) Explain basic UPFC control scheme. [4]

PART ?B (3×16 = 48 Marks)2. a) List various FACTS controllers with their control attributes. [8]
b) Explain loss and speed of switching in high power FACTs devices. [8]

3.
Explain operation of single phase full wave voltage source converter with a neat
circuit and necessary waveforms.
[16]

4. a) List advantages and disadvantages of current source versus voltage source
converters.
[8]
b) Explain how equal area criterion helps to evaluate effectiveness of shunt
compensation and other flow control techniques on transient stability
improvement.

[8]

5. a) Explain implementation of functional control scheme for damping power
oscillations in power system.
[8]
b) Explain basic circuit arrangement of Thyristor ? Switched Series Capacitor (TSSC) with its principle of operation.
[8]

6. a) Explain in detail about basic thyristor ? controlled series capacitor scheme. [8]
b) Illustrate effect of capacitor voltage reversal by TCR. [8]

7. a) Explain capability of UPFC to control real and reactive power flow in
transmission line.
[8]
b) Explain functional control of shunt and series converter. [8]

Code No: RT42023C
Set No. 3
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) List and explain briefly important controllable parameters that are considered
for power flow control.
[4]
b) Explain basic principle of voltage source converter. [4]
c) Explain necessity of VAR compensation in transmission system. [3]
d) Explain different losses that are encountered with FC ? TCR arrangement. [4]
e) List merits of Hybrid compensator. [3]
f) Explain main objectives and usefulness of UPFC in power industry. [4]

PART ?B (3×16 = 48 Marks)2. a) Name and explain different types of stability issues that limit transmission
capability.
[8]
b) What are FACT controllers and explain different categories of FACT
controllers
[8]

3.
Explain the operation of three phase full wave bridge type voltage source
converter with a neat circuit along with the necessary waveforms
[16]

4. a) Explain prevention of voltage stability with the help of end of line voltage
support.
[8]
b) Explain basic operation of Thyristor Switched Capacitor with necessary
waveforms.
[8]

5. a) Explain with a neat block diagram general control scheme of Static Var
Compensator (SVC).
[8]
b) What is transient stability? How attainable enhancement of transient stability
can be done by SVC and STATCOM?
[8]

6. a) Explain with a neat functional diagram, implementation of Var Reserve (operating point) control for damping of Power oscillations in the system.
[8]
b) Explain about basic GTO-controlled series capacitor with principle of operation
and necessary waveforms.
[8]

7. a) Give a comparison between UPFC to IPFC. [8]
b) Explain principle of operation of IPFC with neat diagram. [8]

Code No: RT42023C
Set No. 1
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) Explain need of transmission interconnection. [3]
b) Distinguish between current source and voltage source converters. [4]
c) Explain need of dynamic voltage control in a transmission system. [4]
d) List different methods of controllable VAR generation [3]
e) Explain important features of GTO thyrister controlled series capacitor. [4]
f) Explain the importance of Interline power flow controller(IPFC) [4]

PART ?B (3×16 = 48 Marks)2. a) Explain different dynamic stability considerations that were taken for a
transmission interconnection.
[8]
b) Explain relative importance of different types of FACTS controllers. [8]

3. a) Explain reasons for possessing harmonics in a single phase bridge circuit and
how it can be nullified.
[8]
b) Explain operation of three phase full wave diode converter (neglecting
commutation angle) with a neat circuit and necessary waveforms.
[8]

4. a) Explain the operation of two-machine Power system with an ideal midpoint
reactive compensator with an equivalent circuit and necessary phasor diagram.
[8]
b) Explain in detail about power oscillation damping and why it is considered as
dynamic event.
[8]

5. a) Explain TSC ? TCR type static var generator with a neat functional control
Scheme.
[8]
b) Explain with reasons, why static compensator is not used as a perfect terminal
voltage regulator but allowed to vary in proportion with compensating current.
[8]

6. a) Explain main elements of the overall static compensator control system. [8]
b) Explain concept of voltage stability and improvement of transient stability. [8]

7. a) Discuss the features of UPFC. [6]
b) Explain the basic operating principles and characteristics of Interline Power
Flow Controller (IPFC).
[10]

Code No: RT42023C
Set No. 2
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) Explain concept of power flow in ac system and explain difference when one of
the parallel path is replaced with HVDC transmission.
[4]
b) Explain reasons for absence of neutral connection in a full wave circuit. [4]
c) List functional requirements of reactive shunt compensators. [3]
d) List major functions pf TSC ?TCR type Var generator. [4]
e) Explain basic idea behind series capacitive compensation. [3]
f) Explain basic UPFC control scheme. [4]

PART ?B (3×16 = 48 Marks)2. a) List various FACTS controllers with their control attributes. [8]
b) Explain loss and speed of switching in high power FACTs devices. [8]

3.
Explain operation of single phase full wave voltage source converter with a neat
circuit and necessary waveforms.
[16]

4. a) List advantages and disadvantages of current source versus voltage source
converters.
[8]
b) Explain how equal area criterion helps to evaluate effectiveness of shunt
compensation and other flow control techniques on transient stability
improvement.

[8]

5. a) Explain implementation of functional control scheme for damping power
oscillations in power system.
[8]
b) Explain basic circuit arrangement of Thyristor ? Switched Series Capacitor (TSSC) with its principle of operation.
[8]

6. a) Explain in detail about basic thyristor ? controlled series capacitor scheme. [8]
b) Illustrate effect of capacitor voltage reversal by TCR. [8]

7. a) Explain capability of UPFC to control real and reactive power flow in
transmission line.
[8]
b) Explain functional control of shunt and series converter. [8]

Code No: RT42023C
Set No. 3
R13
1 of 1

IV B.Tech II Semester Regular/Supplementary Examinations, April – 2018
FLEXIBLE ALTERNATING CURRENT TRANSMISSION SYSTEMS (Electrical and Electronics Engineering)Time: 3 hours Max. Marks: 70
Question paper consists of Part-A and Part-B
Answer ALL sub questions from Part-A
Answer any THREE questions from Part-B
*****

PART ?A (22 Marks)1. a) What are the benefits with FACTs controller? [3]
b) Distinguish between self-commutating converters with line-commutating
converters.
[4]
c) Explain different methods of controllable VAR generation. [4]
d) Explain basic operating principle of reactive power generation by a rotating
synchronous compensator (condenser).
[4]
e) List general objectives of series compensation. [4]
f) What do you mean by dynamic performance of UPFC? [3]

PART ?B (3×16 = 48 Marks)2. a) What do you mean by loading capability and explain different kinds of
limitations?
[8]
b) Distinguish between shunt connected controllers with series connected
controllers.
[8]

3. a) Explain techniques that are realized for harmonic elimination and voltage
control.
[8]
b) Explain basic concept of current-source converter. Explain operation of 3-F
CSC.
[8]

4. a) Distinguish in terms of merits and demerits for a two machine transmission
power system w.r.t midpoint voltage support and End of line voltage support.
[8]
b) Explain operation of basic thyristor-controlled reactor with waveforms. [8]

5. a) Explain basic Fixed Capacitor?Thyristor-Controlled reactor type Static Var
Generator with a neat circuit and its output characteristics.
[8]
b) Explain in detail about steady ? state relationship or V-I characteristic of static
VAR compensator.
[8]

6. a) Compare between STATCOM and SVC in terms of operational and performance
characteristics along with application benefits.
[8]
b) With a neat diagram, explain operation of thyrister switched series capacitor. [8]

7. a) Explain the basic operating principles of UPFC with a conceptual representation. [8]
b) Compare between UPFC with IPFC. [8]
Code No: RT42023C
Set No. 4
R13
1 of 1