GTU BE 7th Semester POWER SYSTEM ANALYSIS Summer 2018 Question Paper

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Seat No.: ________ Enrolment No.______________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- VII
SEMESTER ?EXAMINATION ? SUMMER 2018
Subject code:170807 Date: 28-04-2018
Subject Name: POWER SYSTEM ANALYSIS
Time: 02:30 pm to 05:00 pm Total Marks: 70
Instructions
1. Make suitable assumptions wherever necessary.
2. Figures to the right indicate full marks.
3. Each question carry equal marks (14 marks)
Q.1
(a) Derive the per unit model of a single phase transformer. 7
(b) Define per unit system. Derive the formulae of per unit impedance with
usual notations.
7

Q.2 (a) Derive the formulae for peak to peak value of symmetrical short circuit
current for the transmission line subjected to short circuit under no load
condition.
7
(b) (b)Draw the oscillogram of an alternator subjected to symmetrical fault.
Describe the various terminology used for it.
OR
Discuss the factors affecting the selection of circuit breaker.
7

7

Q.3 (a) State the percentage occurrence of unsymmetrical fault. What is a ? With
usual notations prove that 1+ a+a
2
=0.
7
(b) Briefly explain the significance of positive sequence impedance and
positive sequence network model of alternator for fault analysis.
7
OR
Q.3 (a) (b)With usual notations prove that [Vp] = [A] [Vs].
Explain the various configuration of zero sequence networks of
transformers.
7
7
Q.4
(a) Derive the formulae for positive sequence current Ia1 when 3 phase
transmission line is subjected to double line to ground fault.
7
(b) Draw the connection of sequence network for the following cases of open
conductor fault. (i) one conductor open (ii) two conductor open
OR
7
Q.4 (a) (b)State the comparisons for various methods of load flow solutions.

Explain the fast decoupled load flow solution method .
7
7

Q.5 (a) Derive the equation of per unit value of moment of inertia for the
synchronous machine subjected to acceleration due to input feed of
mechanical energy.
7
(b) Describe equal area criterion with. Usual notations. 7 1/2
Seat No.: ________ Enrolment No.______________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- VII
SEMESTER ?EXAMINATION ? SUMMER 2018
Subject code:170807 Date: 28-04-2018
Subject Name: POWER SYSTEM ANALYSIS
Time: 02:30 pm to 05:00 pm Total Marks: 70
Instructions
1. Make suitable assumptions wherever necessary.
2. Figures to the right indicate full marks.
3. Each question carry equal marks (14 marks)
Q.1
(a) Derive the per unit model of a single phase transformer. 7
(b) Define per unit system. Derive the formulae of per unit impedance with
usual notations.
7

Q.2 (a) Derive the formulae for peak to peak value of symmetrical short circuit
current for the transmission line subjected to short circuit under no load
condition.
7
(b) (b)Draw the oscillogram of an alternator subjected to symmetrical fault.
Describe the various terminology used for it.
OR
Discuss the factors affecting the selection of circuit breaker.
7

7

Q.3 (a) State the percentage occurrence of unsymmetrical fault. What is a ? With
usual notations prove that 1+ a+a
2
=0.
7
(b) Briefly explain the significance of positive sequence impedance and
positive sequence network model of alternator for fault analysis.
7
OR
Q.3 (a) (b)With usual notations prove that [Vp] = [A] [Vs].
Explain the various configuration of zero sequence networks of
transformers.
7
7
Q.4
(a) Derive the formulae for positive sequence current Ia1 when 3 phase
transmission line is subjected to double line to ground fault.
7
(b) Draw the connection of sequence network for the following cases of open
conductor fault. (i) one conductor open (ii) two conductor open
OR
7
Q.4 (a) (b)State the comparisons for various methods of load flow solutions.

Explain the fast decoupled load flow solution method .
7
7

Q.5 (a) Derive the equation of per unit value of moment of inertia for the
synchronous machine subjected to acceleration due to input feed of
mechanical energy.
7
(b) Describe equal area criterion with. Usual notations. 7
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OR

Q.5 (a) (b) Derive the swing equation describing the rotor dynamics for synchronous
machines.
Discuss the conditions for parallel operation of generators.
7
7