Dept.
of Electrical Engineering
Branch & Year: B.Tech (4rd Year)
Subject: Switch Gear and Protection
Assignment4
1. Write a short note on
types of time-current characteristics of an overcurrent relay. Classify various-
2. Give overcurrent relays and give their applications.
3. schemes of for a parallel feeder fed from (i) one end (ii) both the ends.
protection
Using carrier system
carrier system? of protection, what is the basis of choice of frequency in power line
4. Compare merits and demerits of various pilot wire relaying schemes for protecting
transmission
lines.
J What do youunderstand by IDMT relay? Draw the typical characteristic of an IDMT relay.
6. Compare electromagnetic relays with static relay.
. Explain the zonalprotection scheme for feeder. Describe the reactance relay characteristic
for 3-zone protection, Also draw the contact circuit for the same.
8. Explain with a suitable example the phenomenon of auto reclosing.
9. Explain the term pilot with reference to power line protection. What are different typesof
pilot schemes?
10. What is distance relay? Draw its characteristic. How is directional feature added with over
impedance relays? Why it is required.
