Anna University Coimbatore 2009 B.E Electrical and Electronics Engineering Ransmission & distribution - Question Paper

ANNA UNIVERSITY- COMBATORE
B.E./ B.TECH. DEGREE exam - JUNE 2009.
ELECTRICAL & ELECTONICS ENGG. - 4th SEMESTER
GENERATION, TRANSMISSION & DISTRIBUTION
PART-A
ans all ques.. (20*2=40)
1. elaborate the various gases delivered through the statch of a thermal power plant.
2. elaborate the function of a control rod in a nuclear plant.
3. Which areas are most potential for wind power generation in India.
4. elaborate the various materials used for power generation using solar power.
5. elaborate the primary constants of transmission lines.
6. Write the expression for the loop inductance of a single phase 2 wire system.
7. What is ASCR conductor.
8. State the importance of skin and proximity effects.
9. describe regulation of a transmission line.
10. What is ferranti effect.
11. State the applications of power circle diagram.
12. List the factors affecting the corona loss.
13. What is safety factor of insulator.
14. Compare and contrast: UG cabling and cabling done using transmission lines.
15. What is the purpose of a metallic sheath in a cable.
16. What is grading of cables. state its importance.
17. List the different drawbacks of a radial system.
18. describe concentrated load. How does it act on AC distribution.
19. Why HVDC lines do not require any reactive power compensation.
20. Which is the 1st HVDC link in the world.
PART-B
ans any five. (5*12=60)
1. a) Compare the thermal and hydro power generating plants in respect to environmental, load management, reserve capacity, waste disposal aspects. (8) b) Draw the layout of nuclear power plant. (4)
2. a)Derive the inductance of a 3 phase transmission line with unsymmetrical spacing. (8) b) A 3 phase overhead transmission line has its conductors organizes at the corners of an equilateral triangle of 2M side. compute the capacitance of every line conductor per km. provided the radius of every conductor is 0.65cm. (4)
3. Determine the subsequent for a single circuit transmission line delivering a load of 45MVA at 132KV and 0.8 pf lagging. The constants of the line are A=D=0.99/_20 and B=105/_800 ohm/phase. Determine (1) sending end voltage and power. (2) sending end active and reative power. (3) line losses and the VAR's absorbed by the line. (4) capacity of static compensation equipment at the receiving end to decrease the sending end voltage to 138KV for the identical load condition. (5) the unity pf load which can be supplied at the receiving end with 132KV as the line voltages at both ends. (12)
4. a) A three unit insulator is fitted with a guard ring . The capacitance of the link pins to metal work and gaurd ring can be presumed to be 20% and 8% of the capacitance of every unit. Determine the voltage across every disc as a percentage of total voltage, string efficiency. (8) b) The capacitance per km of a 3 phase belted core cable is 0.2micro farad/km ranging from 2 cores with the 3rd core connected to sheath. compute the KVA. The supply voltage is 6.6KV and 30km long. (4)
5. An electric train taking a constant current of 500A moves on a part of line ranging from 2 stations 10 km apart and maintained at 600 and 590 volt respectively. The track resistance is 0.05ohm/km both go and return. obtain the point of minimum potential along the track and current supplied by 2 substations at that instant. (6) b) discuss the STATCOM and UPFC. (6)
6. a) Derive the expression for capacitance of a 3 phase double circuit line flat vertical spacing with transposition. (8) b) Write short notes on inductive interface with neighbouring circuits. (4)
7. a) Determine the efficiency and percentage regulation of a 3 phase 100 km 50 Hz transmission line delivering 20MW at a pf of 0.8 lag 66KV to a balanced load. The conductors are of copper every having resistance 0.1 ohm/km 1.5cm outside dia spaced equilaterally 2m ranging from centres. neglect leakage reactance and use nominal pi method. (8) b) Draw the receiving end circle diagram for short line. (4)
8. a) Derive an expression fr stepped and tapped mains a1/a2 =\l (l1+l2)/l1. (8) b) discuss the issues involved and environmental aspects in EHVAC transmission. (4)

Earning:   Approval pending.