52110-mt----advanced Power System Protection

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Code No: 52110/MT M.Tech. – I Semester Supplementary Examinations, September, 2008 ADVANCED POWER SYSTEM PROTECTION (Power System Control & Automation) Time: 3hours

Max. Marks:60 Answer any FIVE questions All questions carry equal marks ---

1.a) b)

What is meant by a zone of protection? Discuss various zones of protection for a modern power system. Discuss different types of PT’s with their areas of applications.

2.a)

What are the various over current protective schemes? Explain their merits and demerits. b) What are the advantages of static relays over electromagnetic relays?

3.

What is an impedance relay? Explain its operating principle. Discuss how it is realised using the: i) Electromagnetic principle ii) Amplitude comparator iii) Phase comparator.

4.a) What is carrier current protection? For what voltage range is it used for the protection of transmission lines? b) What is carrier aided distance protection? What are its different types? 5.

Describe a digital technique for the removal of the DC offset component from the current signal.

6.

What is a single chip microcomputer? Describe the latest 8- bit single chip micro controller.

7.

Derive a generalised mathematical model of distance relays for digital protection.

8.

Explain the block schematic diagram of the 8086 microprocessor based digital distance relays. *****