English, asked by Devdongre, 5 months ago

The number of pilot wire required for protecting 3-
phase transmission lines using translay system of
protection is​

Answers

Answered by priyaag2102
0

Number of pilot wire required are Two

Explanation:-

Number of pilot wires required for protecting 3-phase transmission lines using translay system of protection are two

The principal reason is that there would have tobe too many interconnections between current transformers (CT’s) to make current-differential relaying economically feasible over the usual distances involved intransmission-line relaying. For a three-phase line, six pilot conductors would be required,one for each phase CT and one for the neutral connection, and two for the trip circuit.

Because even a two-wire pilot much more than 5 to 10 miles long becomes more costly than a carrier-current pilot, we could conclude that, on this basis alone, current-differential relaying with six pilot wires would be limited to very short lines.

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