AU Solved Paper

AU Solved Paper [50482]

December - 2017

Transmission and Distribution

Semester - IV (EEE) (Regulation 2013)

 

[Time          : Three Hours]    

[Maximum Marks : 100

 

Answer ALL questions

PART - A (10 x 2 =       20 Marks)

 

Q.1 What is interconnected system ?

[Refer Two Marks Q.44 of Chapter - 7]

Q.2 What is the objectives of FACTS ?

 [Refer Two Marks Q.17 of Chapter - 7]

Q.3 Why the concept of self GMD is not applicable for capacitance calculation ?

[Refer Two Marks Q.44 of Chapter - 1]

Q.4 What is transposition ? Why are transmission line transposed ?

[Refer Two Marks Q.45 of Chapter - 1]

Q.5 How are transmission line classified ?

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

Q.6 What is Ferranti effect ?

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

Q.7 What is a belted-cable ?

[Refer Two Marks Q.34 of Chapter - 6]

Q.8    What are the desirable properties of insulator ?

[Refer Two Marks Q.10 of Chapter - 5]

Q.9    What are the major equipments of a substation ?

[Refer Two Marks Q.17 of Chapter - 8]

Q.10  Give the significance of a stringing chart.

[Refer Two Marks Q.2 of Chapter - 4]   

         

PART - B (5 × 13 = 65 Marks)

Q.11 a) i) Draw and explain the structure of typical electrical power system with various voltage levels.

 [Refer section 1.2]        [8]

ii) Draw and explain a simple model of UPFC.

[Refer section 7.29.4]    [5]

OR

b) i) Briefly discuss the technical advantages of HVDC over HVAC transmission system.

[Refer section 7.25.2]    [8]

ii) Explain the applications of HVDC transmission system.

[Refer section 7.25.4]    [5]

Q.12 a) Describe the expression for calculating the internal and external flux linkages for a conductor carrying current. Use these expressions to derive the equation for the inductance of a single - phase transmission line.

[Refer sections 1.11 and 1.12][13]

OR

b) Derive an expression for capacitance of a three overhead line.

[Refer section 1.30]

Q.13 a) i) Draw the phasor diagram of a short transmission line and derive an expression for voltage regulation and transmission efficiency.

[Refer section 2.7] [7]

ii) A three - phase transmission line having a series impedance of (20 + j30) Q delivers 7 MW at 33 kV and 0.8 lagging power factor. Find the sending end voltage, regulation and power angle. Neglect shunt capacitance.

[Refer example 2.7.4]   [6]

OR

b) i) Deduce the expression for the sending end and receiving end power of a transmission line in terms of voltages and ABCD constants.

[Refer section 2.14]       [7]

ii) Briefly explain the procedure of drawing receiving end power circle diagram.

[Refer section 2.15]       [6]

Q.14 a) With neat diagram, explain the various methods of grading of underground cables.

[Refer section 6.8]         [13]

OR

b) i)   Discuss the constructional features of pin type insulators.

[Refer section 5.3.1] [7]

ii) An insulator string consists of three units each having a safe working voltage of 15 kV. The ratio of self - capacitance to shunt capacitance is 6 : 1. Determine the line voltage and string efficiency.

[Refer example 5.5.1] [6]

Q.15 a) i) Prove that a transmission line conductor between two supports at equal heights takes the form of a catenary.

[Refer section 4.6] [7]

ii) What is a sag - template ? Explain how this is useful for location of towers and stringing of power conductors.

[Refer section 4.9]         [6]

OR

b) Describe about the various methods of neutral grounding in detail.

[Refer section 8.13]

 

PART - C (1 × 15 = 15 Marks)

Q.16 a) Derive the expression of capacitance of a bundled conductor.

[Refer section 1.32]

OR

b) Discuss the methods of range of voltage control in transmission line.

[Refer section 7.18]