1 / 3

Why is it Important to Set Date and Time in Numerical Relays?

Numerical relays help in protecting different electrical equipment like generator, transformers, transmission lines, and motors. Therefore, many simple yet important things need to be checked with a Numerical Relay, like its running time (which can be manually set), current clock time, and current date.

systemprotection
Download Presentation

Why is it Important to Set Date and Time in Numerical Relays?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ISO 9001:2015 ISO 45001:2015 (OH & S) Certified Company Case Study Why is it Important to Set Date and Time in Numerical Relays? www.systemprotection.in +91-265-2225137

  2. Numericalrelayshelpinprotecting differentelectricalequipmentlike generator, transformers, transmissionlines, andmotors. Therefore, manysimpleyet importantthingsneedtobecheckedwitha NumericalRelay, likeitsrunningtime (whichcanbemanuallyset), currentclock time, andcurrentdate. OnemightarguethatFault1isthelatest butinthetimebetweenthebreakdown andwhentheteamreachedthesitefor datacollectionforFaultanalysiswhichwas 7dayslater, therewasonemoretripping duetoovercurrent. So, aftercheckingFault inother11kVrelaysthatweretrippedthat day, theteamfoundthatFault2wasactual forwhichtheteamhadtoanalyzeforthe breakdownthatoccurredon14thFebruary 2016. Now, it'scommonthatmanypeopleask whyitisimportanttosetdateandtime. Thiscanbewellexplainedwiththehelpof today'scasestudyaboutatypicalindustrial system. Inoneincident, therewasa breakdownofonesectionduetofaultin11 kVtransformerfeeder (Remote). This resultedinthecascadedtrippingandit wentontillthe66kVIncomerfromthegrid tripped. Theproblemwasofrelayco- ordinationbutonanalysis, itwasobserved thatthiswasnotcompletelytherelay coordinationissue. Youcancheckoutthis casestudyexplainingtheimportanceof relayco-ordinationinProcessindustries. Generally, relaylosessynchronismwhen relaysauxiliarysupplyislostforaverylong time, whichusuallyhappensduringthe routineshutdownforaparticularunitfor3 – 4daysormorethanthat. Thereisno solutionforthisotherthansynchronizing relayclockwithIndianStandardTime whenevertheauxiliarysupplyisturnedon. Apartfromthisthereanyproblemsdueto impropersettingofdateandtime. Like, Erroneousrecordsofallfaultsandevents andthiserroneousanalysismayleadtothe re-occurrenceofthesameeventswhich againleadstowastageofproductivetime. Thesolutionistoensurethatthereisproper synchronizationoftherelayclockwithDCS / GPS / SCADA. Thisishelpfulespeciallyin thecase, theauxiliarysupplyisoutof serviceforalongerdurationoftime. Also, checkingrelayparametersatregular intervalsshouldbedonetoavoidsuch issues. Theteamwascalledfortroubleshooting. Thefirststepthatwastakenwastotake faultrecordsofallfiverelaysalongwiththe existingsettings. Whilechecking, itwas observedthatboththerelayswereshowing properdateandtimebuthadnofault recordsmatchingtheotherthreerelays. Instead, theywereshowingthewrongdates (from6monthsto6years) beforethe incident. Onenquiring, theteamcametoknowthat inboththerelaysdateandtimesettings weremodifiedbyaplanttechnicianpost theoccurrenceofthefault. Afterlengthy discussionswithmanypersonnelinvolved andsiftingfaultrecordsminutely. Eventually, wecouldzero-inonwhich recordstointerpretandbasedonthathow cantheteamconsult; aseemingly10 minutesexerciselengthenedtoabout8 hours. TheretrieveddataoftheFault Recordwassomethinglike Fault1: 19thFebruary2016 (OverCurrent) Fault2: 12thSeptember2013 (Earth - Fault) Fault3: 16thJuly2015 (OverCurrent) www.systemprotection.in +91-265-2225137

  3. CONTACT INFORMATION 301/2/306, SilverlineComplex,OppositeBBC Tower,Sayajigunj,Vadodara - 390005, Gujarat, India. bdm@systemprotection.in www.systemprotection.in +91-265-2225137

More Related