THE SCIENTIFIC STUDY OF N.P.S. RELAY OPERATION IN REY GAS POWER PLANT

In The negative phase sequence current . the resulting current am very Large and Cause severe heeting of the rotor. So sievereis thin effect that a single-phase load equal to the normal three-ohase rated current em quickly heat the bress rotor dot then to the softening point ; they may then be extruded under centrifugal force until they stand above the rotor surface . when it in possible that they may strike the start iron.Concentration of heating occurs on portion* of the coil binding ringe and hare surface fuition how been knownto occur. The negetive Sequence relay provides sensitive phase unbalance detection . and designed to protect generators against prolonged contribution to externel unbalance faults. In operntion of the Protection from start ing of Rey am Power Plant (IRAN) up to end of 1371(1993) by using of Recorded events in studied Result show during this peroid , the relay have hod 29 operationsthat am related to 11 generators from 40 units in this power plant