7/24/2019 Quiz 2 EE 352 Electrical Machines

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EE 352: Electromechanical Systems

Quiz 2: Transformers 

Name Roll No.

SMOKING IS INJURIOUS TO HEALTH AND SO IS PLAGIARIZING IN THIS COURSE

1. 

There are two Distribution Lines outside Shibal’s House, one of them operating at 13.2KV and the

other at 13.8KV. Nauman made an autotransformer and wants to use it to connect the twodistribution lines. However this is subjected to the following condition.

“  The autotransformer must operate at 600KVA at  both its INPUT  and OUTPUT ” .

Answer the following questions.

a) 

What turns ratio must be used to support this connection at the mentioned power level? [4]

b) 

Draw the transformer connections at the mentioned power level, properly labelling currents

and voltages at both the high and low voltage sides. [4]

c) 

Point out qualitative and quantitative differences b/w the configuration above and the normal 

autotransformer configuration. [4]d)  Dost wants to make a nameplate for this autotransformer. At what power should it be rated? [4]

e) 

Shibal argues to connect a normal transformer rather than an autotransformer. How and why 

would the following change? (No marks for how without why) [4]

i) Voltage regulation

ii) Voltage rating of the low voltage side

iii) Current limiting capability during short circuit faults.

iv) Isolation b/w the distribution lines.

Best of Luck