Protection and commissioning of digital transformer relays.

Protection and commissioning of digital transformer relays.

Need of digital relay phasing standards capability ,CT requirement How to communicating requirements.AbstractEquipment (cables)Reduce voltage dipsReduce damage of point

Advantages of sensitive groundingAbnormal conditions(over excitations ,older)Frequent faultsInfrequent faults(most of the medium transformers are line to ground faults)Reasons for transformer failureIn EM relays 6tap to balance the current magnitudes on primary and secondary mismatching 3:1 and digital relays continuous tap settings mismatch of 10:1

In digital protection CTs are connected in Delta the magnitude of normal condition to set1.73 times of the individual load current.

Transformer Differential ProtectionRecordingMultiple setting groupsMultiple output and input contactsMeteringMonitoring of external input /outputsProgrammable logicSelf monitoring

Applications of digital transformer relaysMore complicated they also programmed logic which must be verifiedCommissioning .this is complexityDetermining whether properly connect to the CT and PTs

Testing of digital relaysInjection of current and voltage into the relay setting and timingrelay input and output contactsrelay logictripping and targets

Commissioning testingMany relay operations perform on single hardware platform if platform damage there is protectionAnd also testing difficult conclusion