Distance Protection Scheme

hi,

Distance protection is nothing but impedence protection. Used mainly in long transmission lines , having 2 or more substations in a line. Impedence protection relay is used to locate the exact position of fault in a line, there by decides which substation breaker should trip.

e.g. generating station with 132kv transmission having 25 km long line, having 132/33kv substations at point A - 5 km distance, B - 15 km & C - 25 km distances. We have installed distance protection relays in substation A, B, & C.

If fault occures after point C, it is preferred that distance relay in substation C should trip first. then if it failes, then relay in Point B should trip as a back up protection.

Dear Harry

Thankyou for your reply.

But I mean different schemes using in distance protection like transfer tripping & blocking. I know about the distance protection.

Rgds

BRN

Sir

Please like to tell me about the working principle of this Distance Relay and how it locates the exact position of fault, on what kinds of faults it activates. Please explain with its connection diagram or please give me some site address or E-Book address if you have.

Regards

JK

k sir how it detect the location