AU Solved Paper

AU Solved Paper [71773]

May - 2017

Transmission and Distribution

Semester - IV (EEE) (Regulation 2013)

 

[Time : Three Hours]    

[Maximum Marks : 100]

 

Answer ALL questions

PART A - (10 × 2 = 20 Marks)

 

Q.1 Mention the transmission voltages that are followed in Tamil Nadu.

[Refer Two Marks Q.42 of Chapter - 7]

Q.2 What is ring main system ?

[Refer Two Marks Q.36 of Chapter - 7]

Q.3 State skin effect in transmission lines. Mention its effect on the resistance of the line.

[Refer Two Marks Q.3 of Chapter - 1]

Q.4    State different types of overhead conductors.

[Refer section 1.4]

Q.5    What is Ferranti effect ?

[Refer Two Marks Q.6 of Chapter - 2]

Q.6 Write down the significance of SIL on transmission line.

[Refer Two Marks Q.21 of Chapter - 2]

Q.7 Specify the different types of insulators.

[Refer Two Marks Q.7 of Chapter - 5]

Q.8 What are the two different methods of grading of cables ?

[Refer Two Marks Q.15 of Chapter - 6]

Q.9 Enlist any two factors that affect sag in the transmission line.

[Refer Two Marks Q.5 of Chapter - 4]

Q.10 Write down the types of grounding.

[Refer Two Marks Q.10 of Chapter - 8]

 

PART B - (5 × 13 = 65 Marks)

Q.11 a) Explain the structure of electric power syatem in detail.

 [Reier section 1.2] [8]

OR

b) i) Compare the overhead and underground distribution system.

[Refer section 1.3.3] [8]

ii) State the advantages of interconnected system.

[Refer section 7.6.4]      [5]

Q.12 a) Explain the factors affecting corona loss and methods of reducing corona loss.

[Refer section 3.3]

OR

b) i) Explain the advantages of bundled conductors when used for overhead lines.

[Refer section 1.4.16.1] [4]

ii) Determine the inductance of a 3 phase line opearating at 50 Hz and the conductors are arranged as shown below. The conductor diameter is 0.7 cm.

[Refer example 1.19.6] [9]

Q.13 a) What are the different methods available for voltage control and explain any one method.

[Refer section 7.18]

OR

b) i) Explain the meaning of performance of lines.

 [Refer section 2.4]        [5]

ii) A single phase 50 Hz generator supplies an inductive load of 6 MW at 0.8 pf lagging by means of an overhead line 15 km long. The line resistance and inductance are 0.02 ohm/km and 0.85 mH/km. The voltage at the receiving end is 11 kV. Determine the sending end voltage and voltage regulation.

[Refer example 2.5.1]   [8]

Q.14 a) What are the different types of testing of insulators ? Explain any one method.

[Refer section 5.7]

OR

b) Write short notes on :

i) Properties of insulation material used for cable.

 [Refer section 6.5.1]     [5]

ii) The capacitance per kilometer of a 3 phase belted core cable is 0.2 micro farad/km between two cores with the third core connected to sheath. Calculate the kVA. The supply voltage 6.6 kV and 30 km long.

 [Refer example 6.9.4] [8]

Q.15 a) Describe the different types of substation layouts and list few advantages of GIS.

[Refer sections 8.5, 8.6 and 8.9.1]

OR

b) Explain the key points to be considered for tower spotting. Also list the basic types of tower based on circuits used.

[Refer sections 4.9 and 4.11]

 

PART C - (1 × 15 = 15 Marks)

Q.16 a) A 400 V, 3 phase 4 wire service mains supplies a star connected load. The resistance of each line is 0.1 ohm and that of the neutral 0.2 ohm. The load impedances are ZR - (6 + j 9), Zy - 8 ohms and ZB - (6 - j 8). Calculate the violtage across each load impedance and current in the neutral. Phase sequence RYB.

[Refer example 7.13.4]

OR

b) Explain your understanding about transmission of power and distribution of power.

[Refer sections 1.2 and 1.3]