Describe the operation of current differential relay with neat sketch.

Describe the operation of current differential relay with neat sketch.
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1 Answer

Answer :

Operation of Current Differential Relay:

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Figure shows an arrangement of an overcurrent relay connected to operate as a differential relay for alternator protection under fault conditon. Under normal operating conditions, suppose the alternator winding carries a normal current then the current in the two seconderies of CTs are equal. These currents will only circulate between the two CTs and no current will flow through relay coil. If a fault occurs on alternator winding, the two secondary currents will not be equal and resultant current flows through relay coil, causing relay to operate for protection of alternator winding.

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