**PS7005 High Voltage Direct Current Transmission ****Question Bank**

**PS7005 Part A Question Bank**

**M.E - Power Systems**

**3rd Semester - 2nd Year Question Bank**

**Unit I**

1. List the disadvantages of AC Transmission over long distance.

2. Describe the minimum short circuit ratio recommended by CIGRE to ensure feasibility

of DC transmission.

3. Define energy availability.

4. Name the HVDC Transmission in India.

5. Collect the advantages of HVDC Transmission system.

6. List the uses of filters used at converter station.

7. Summarize any two disadvantages of DC transmission.

8. Discuss the types of DC links.

9. Describe the uses of reactive power source at converter station.

10. Summarize the asynchronous tie.

11. Show the Cost Vs distance curve of AC & DC Transmission.

12. Relate the expression for real power flow through the line.

13. Illustrate the components involved in converter station.

14. Point out the limitations of EHVAC Transmission.

15. Differentiate between conventional Transformer & converter Transformer. 16. Point out about multi terminal DC link.

17. Explain about DC breakers.

18. Explain the variation of voltage along the Transmission line during different loading condition.

19. Generalize the surge impedance loading

20. Develop the 12 pulse converter unit

**Unit II**

1. Define pulse number.

2. Describe the rectifier modes.

3. List some faults that can occur in converters.

4. Define Value rating.

5. Identify the assumptions mode to simplify the analysis of Graetz circuit.

6. Quote the assumptions mode to simplify the analysis of Graetz circuit.

7. Summarize the 3 variations of the equidistant pulse control

8. Describe Graetz’s circuit.

9. Distingusih overlap angle and extinction angle

10. Describe the term delay angle and its significance in rectifier control

11. Illustrate mode ambiguity

12. Examine the expression for the average DC voltage of Graetz circuit without overlap.

13. Examine the converter bridge characteristics.

14. Differentiate Charactersitis and uncharacterisisstics harmonics

15. Explain the role of smoothing reactor in a DC link

16. Explain the term angle of advance and its significance in inverter control.

17. Explain how a HVDC value must be designed to withstand over voltage protection.

18. Judge the effect of harmonics on HVDC converter system.

19. Generalize the causes of DC side harmonics

20. Generalize the reason to maintain minimum value of delay angle and extinction angle.

**Unit III**

1. Define current-margin method.

2. List the classification of MTDC system.

3. Tabulate the merits and demerits of series and parallel MTDC systems.

4. Collect the potential application of MTDC systems

5. Describe a multilevel VSC DC system.

6. Name the different types of MTDC system.

7. Discuss the need of MTDC links. Name anyone existing MTDC link in operations.

8. Give three specific areas of MTDC systems.

9. The detection of DC link faults gets complicated in a mesh system.Discuss

10. Give the drawbacks of MTDC system.

11. Classify the control methods used in MTDC systems.

12. Illustrate the drawbacks of voltage limiting control in MTDC system.

13. Show the circuit diagram of a multi infeed system.

14. Point out the typical problems that have to be considered for the study of MTDC system.

15. Explain the term Current reference balancer”

16. Explain two ACR method of control of Multi terminal HVDC link.

17. Judge” Can we extend the two terminal systems to multi terminal system.

18. Discriminate between series and parallel MTDC systems.

19. Develope the bulk power transmission using 2 terminal links diagram.

20. Generalize how to protect the MTDC system.

**Unit IV**

1. List the assumptions made in DC load flow.

2. Define per unit system.

3. List some essentials of power flow analysis.

4. Name the different types of AC/DC power flow.

5. Describe the unified method of DC power flow.

6. List the applications of load flow analysis.

7. Summarize the sequential method of DC power flow.

8. Give the dc system model.

9. Discuss the additional constraints needed to include for AC-DC power flow.

10. Express the Equations Describing the DC network.

11. Illustrate the advantages of variable elimination method over extended variable

method.

12. Show the Norton’s equivalent circuit for a converter.

13. Show the schematic of the dc converter and give the voltage equation.

14. Explain the two solution methodologies for ac-dc power flow.

15. Pointout the flow chart of the ac-dc power flow.

16. Explain about the identical per unit system of the dc converter system.

17. Summarize the different approaches evolved in load flow analysis of HVDC

transmission system.

18. Deduce the schematic diagram of the five terminal HVDC system.

19. Develop the gauss seidal equation for solution of the ac/dc power flow. 20. Evaluate the parameters to control the angle and the transformer tap of the converter.

**Unit V**

1. List any two requirements of a good simulation tool.

2. Define parity simulator.

3. List the parameters that could be determined from HVDC system studies.

4. Tabulate the number of system studies that required for the design of a HVDC system.

5. Collect the problems that can be studied using dc simulator.

6. List the tools that can be employed for the simulation of a dynamic system.

7. Give the EMTP representation of a capacitor.

8. Describe the application of switching functions.

9. Discuss transient network analyser.

10. Give the EMTP representation of an inductor.

11. Show the model of a converter transformer.

12. Illustrate the formulation of state equations for α and β sequence ac network.

13. Show the bipolar HVDC line section model.

14. Explain the tools employed for simulation of a dynamic HVDC system. 15. Pointout the advantages of parity simulator.

16. Explain about parity simulator.

17. Summarize some tools that can be employed for the simulation of HVDC systems.

18. Deduce the physical model of a converter transformer.

19. Generalize the need for simulation of HVDC system.

20. Develop the EMTP Model of valve.