Name of the College : Mahatma Gandhi University
Department : Electrical and Electronics Engineering
Subject Code/Name : MEEPP 106-3/High Voltage Dc Transmission
Sem : I
Website : mgu.ac.in
Document Type : Model Question Paper
Download Model/Sample Question Paper :
I : https://www.pdfquestion.in/uploads/mgu.ac.in/5055-1-MEEPP%20106-3%20High%20Voltage%20DC%20Transmission%20-1.doc
II : https://www.pdfquestion.in/uploads/mgu.ac.in/5055-2-MEEPP%20106-3%20High%20Voltage%20DC%20Transmission%20-2.doc
High Voltage Dc Transmission :
M.TECH. Degree Examination :
Model Question Paper – II
First Semester
Related : MGU MEEPP105-3/MMEPE105-2 Robotics & Automation M.Tech Model Question Paper : www.pdfquestion.in/5054.html
Branch: Electrical Engineering
Specialization: Power Electronics and Power Systems
MEEPP 106-3 High Voltage Dc Transmission (Elective-1)
(2013 Admission onwards)
(Regular)
Time: Three Hours
Maxm. 100 Marks
1 (a) What are the advantages of HVDC when compared to HVAC. [13]
(b) Classify different types of HVDC systems based on :
i. Construction
ii. Application
OR [12]
2 (a) How is HVDC economical when compared to HVAC for bulk power transmission. [10]
(b) How is power flow control achieved in HVDC systems. [08]
(c) Explain the choice of DC voltage for a fixed amount of power transfer . [07]
3 (a) Draw the Graetz circuit and draw the timing diagram considering the overlap greater than 60° and without overlap for
i. Voltage across the load
ii. Voltage across any two conducting pair of valves [15]
(b) Explain the dependency of power factor angle on firing angle (a) . [10]
OR
4. (a) Derive the expression for output voltage across the load for a firing angle less than 60° in the 3-ph bridge circuit. [08]
(b) Draw the Graetz circuit and draw the timing diagram considering the overlap less than 60° and without overlap .Also draw the waveforms of Current in any phase . Specify the assumptions made. [07]
(c) Explain Design requirements of a converter circuit. Show that 3-phase bridge configuration is the most suitable for HVDC link. [10]
5. (a) Explain constant-voltage parallel scheme and constant current series scheme for multi terminal DC lines. [10]
(b) Why is constant current control preferred over constant voltage control [08]
(c) Explain real and reactive power control during steady state and transient conditions [07]
OR
6. (a) Explain in detail control characteristics of Converter in HVDC system. [13]
(b) Explain in detail the reactive power requirement of a converter station. How is the reactive power supplied? [12]
7. (a) Derive the expression for ripple current in the DC current. Draw the waveform of ripple voltage and ripple current for a=30° [13]
(b) What are the effects of Harmonics on the communication systems like telephone line. [12]
OR
8. (a) What are the different scenarios where HVDC lines are subjected to over-voltages. Explain in brief the different overvoltage protection schemes. [13]
(b) Explain in detail the DC line oscillations and the line dampers used. [12]
M.TECH. DEGREE EXAMINATION :
Model Question Paper – I
First Semester
Branch: Electrical Engineering
Specialization: Power Electronics and Power Systems
MEEPP 106-3 HIGH VOLTAGE DC TRANSMISSION (Elective-1)
(2013 Admission onwards)
Time: Three Hours
Maxm. 100 Marks
1 (a) Explain in detail the reasons for preferring HVDC over HVDC for long distance power transmission [10]
(b) How is power flow control achieved in HVDC systems. [08]
(c) Explain the choice of DC voltage for a fixed amount of power transfer . [07]
OR
2 (a) Draw a neat sketch of HVDC transmission scheme and explain the components [13]
(b) Compare HVDC and HVAC based on
i. Stability
ii. Bulk power transfer
iii. Stability [12]
3. (a) Draw the Graetz circuit and draw the timing diagram considering the overlap less than 60° and without overlap for
i. Voltage across the load
ii. Voltage across any two conducting pair of valves [15]
(b) Explain the dependency of power factor angle on firing angle (a) [10]
OR
4. (a) Explain the effect of overlap on the performance of converter. [10]
(b) Among the different converter configurations prove that Graetz circuit is the most suited for HVDC application [15]
5. (a) Explain in detail the reactive power requirements in HVDC terminal equipment. [10]
(b) Why is constant current control preferred over constant voltage control [08]
(c) Why is pf kept high in the AC system connected to the HVDC link. [07]
OR
6. (a) Explain in detail control characteristics of Converter in HVDC system. [13]
(b) Explain real and reactive power control during steady state and transient conditions. [12]
7. (a) Derive the expression for ripple current in the DC current. Draw the waveform of ripple voltage and ripple current for a=30°. [13]
(b) What are the effects of Harmonics on the AC power system. [12]
OR
8. (a) What are the different scenarios where HVDC lines are subjected to over-voltages. Explain in brief the different overvoltage protection schemes. [13]
(b) Explain the importance of smoothing reactors in a DC link. How the commutation failure prevention is achieved . [12]