10 ஐ
b)

11

12

13 a)

b)
14

F1055 Pages: 3

Draw the zero sequence networks of star-delta and delta-delta transformers
Draw and explain the oscillogram of short circuit current when an unloaded
alternator is subjected to a 3-phase fault
Derive the expression for fault current and draw the interconnection of sequence
networks for the following faults on the terminals of an unloaded generator.

(a) single Line to Ground fault

(b) Line to Line fault

PART ட
Answer any two full questions, each carries 10 marks.

The figure shows the SLD of a simple four bus system. The table gives the line
impedance identified by the buses on which these terminate. The shunt

admittance at all the buses is assumed to be negligible.
a) Find ‏,وسنولا‎ assuming that the line shown dotted is not connected.
0) What modifications need to be carried out in ‏ںول‎ if the line shown

dotted is connected

Line, Bus to Bus

0.45
0.30
0.15

Compare between Gauss-Seidal method and Newton-Raphson method, in load

flow studies.

With neat diagram explain the working of a turbine speed governing system.

(5)
(5)

(10)

(10)

(5)

(5)

Derive the generator load model and draw the complete block diagram of a single (10)

area system

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