DISTRIBUTION FEEDER FAULT ANALYSIS...due to 115 kv underbuild. elbow failure on ug. scada alarm at...

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T I L L A M O O K P E O P L E ’ S U T I L I T Y D I S T R I C T

DISTRIBUTION FEEDER FAULT ANALYSIS

SCADA TO DG SITES

DIGESTER MW AND MVAR

INSTANTANEOUS READINGSFROM SEL 751 RELAY

TRASK SUBSTATION LOADINGDO NOT WANT TO FEED INTO 115 KV

FAULT LOCATOR TOOL DEVELOPED BY GIS SPECIALIST

CAR HIT POLE EVENT ANALYSIS

W I L S O N R I V E R S U B S T A T I O N E V E N T O N 9 - 2 - 1 3

WILSON RIVER SUBSTATION, CIRCUIT 63

Car Pole Accident

Olsen Rd.Recloser

Misty MeadowsGeneration

SCADA ALARMS DURING EVENTNOTE: DEVICE TIMES ARE NOT

SYNCHED

DG on adjacent circTripped Open

Olsen Rd. RecloserOperations

Ckt 63 RecloserLocks Out

SOE FROM SUBSTATION RECLOSER

OLSEN RD. RECLOSER OPERATIONS

NEXUS 1500 METER ON SUBSTATION BUS

A PHASE CURRENT – 2 OPERATIONS OF RECLOSER

3RD INTERRUPTION – MUCH HIGHER FAULT CURRENT

SEL 751 AT MISTY MEADOWS GENERATION 480 VOLT BUS

MAX FLT I = 3078 AMPS AT ACCIDENT SITE

SO HOW DID WE GET 4178 AMPS ON THE CIRCUIT 63 SEQUENCE OF EVENTS FILE?

SYNERGI PREDICTS A FAULT OF THIS MAGNITUDE SHOULD BE CLOSER IN TO

THE SUBSTATION

THIS IS SECTION OF LINE THAT SYNERGIPREDICTED THE FAULT SHOULD BE IN

A SHARP EYED OPS SUPV. FOUND BURN MARKS IN THIS VICINITY. LONG SPANS

DUE TO 115 KV UNDERBUILD

ELBOW FAILURE ON UG

SCADA ALARM AT 17:10 INDICATES FAULT ON NESTUCCA FEEDER 39

FIRST STEP IS TO CONNECT TO FORM 6 RELAY OVER ETHERNET – SEQ COORD. MEANS ANOTHER DEVICE OPERATED

OSCILLOGRAPHIC FILE FROM THE FORM 6 RELAY – PEAK CURRENT =1737 A

1737 X .707=1228 A RMS

FAULT LOCATION TOOL THAT GIS SPECIALIST MADE – FLT I FROM SYNERGI PROTECTION STUDY

FAULT WAS ON SINGLE PHASE UG IN SUBDIVISION – ELBOW FAILED

EXTENT OF FEEDERPOSSIBLE LOCATIONS ON MULTIPLE BRANCHES

FIRST RAIN AFTER DRY SUMMER

T I LLAMOOK PEOPLE’S UT I L I TY D ISTR ICT

FIRST INDICATION OF PROBLEMSCADA SHOWS FAULT ON CKT. 64

NEXUS 1500 ON SUB BUS

ZOOM IN ON PHASE A AND B CURRENTS

THE 3 PHASE CURRENTS ON CIRCUIT 64

COMPARE WAVEFORMS TO FORM 62ND PHASE GETS INVOLVED

OUTAGE REPORT SHOWS INSULATOR FLASHED OVER

PROBLEMS AT TCCA BOILERTCCA=T I LLAMOOK CHEESE FACTORY

FORM 6 OSCILLOGRAPHPEAK CURRENT = 3820 AMPSRMS CURRENT = 2700 AMPS

NEXUS 1500 ON SUB BUS

NEXUS FAULT CURRENT IS CLOSE TO FORM 6 VALUE = 3900A X .707=2757 A,

NOTE DROP IN LOAD

FROM SYNERGI, FAULT CURRENT AT BOILER MATCHES MEASURED FAULT I

FAULT LOCATOR TOOL PRETTY CLOSE

TREE THROUGH LINEMOHLER CIRCUIT 91

RECLOSER AT SUB SHOWS 428 A FAULT CURRENT ON C PHASE

OSCILLOGRAPH FROM FORM 6 SHOWS FOUR CYCLES OF FAULT CURRENT

4 CYCLES = .066 SEC.

FAULT BLEW A 15 A FUSE AT FISH HATCHERY

TCC CURVE SHOWS THAT 15 A FUSE SHOULD BLOW IN .06 SEC. AT 425 AMPS

FAULT LOCATOR TOOL TURNED OUT TO BE FAIRLY ACCURATE

Fuse Blew Here

Tree throughLine Here

SYNERGI PREDICTS 411 AMPS FAULT CURRENT AT THIS LOCATION

F A U L T E V E N T O N 1 1 - 9 - 1 5

STARLING BRINGS DOWN BLUE HERON

TUESDAY MORNING AT 8:20 AM

• Public Relations called Operations to find out if a breaker operated at Wilson River Substation• The Mill in town called to report a power dip

• SCADA showed that Circuit 61 had operated and Circuit 62 (Mill Feeder) saw current above Min Trip

ENGINEERING CONNECTED TO FORM 6 RECLOSER CONTROLS AT SUBSTATION VIA ETHERNET

• The Sequence of Events report from Ckt 61showed that the recloser tripped on Overcurrent, then reclosed and reset

ALSO DOWNLOADED OSCILLGRAPHYFILES FROM THE RECLOSERS

• Confirmed fault on Ckt 62

CONTINUATION OF WAVEFORM ON PRIOR SLIDE

• Note that second phase gets involved in fault in the last couple cycles before interruption

AFTER THE RECLOSER RECLOSED THE TRANSFORMER MAGNETIZING CURRENT WAS PRESENT

• After a few cycles, the magnetizing current decayed to below the minimum pickup value

NEXUS 1500 METER MONITORING THE TRANSFORMER BUS GIVES A BETTER PICTURE OF THE EVENT

• Note that 2nd phase gets involved before breaker opens. And transformer inrush currents can be seen

ZOOMING IN TO PHASE B

• The recloser was open for 2010 ms (2 sec.)

PLUGGED FAULT CURRENTS INTO FAULT LOCATOR TOOL TO PREDICT LOCATION OF FAULT

• Area highlighted in red is most likely fault location

BLUE HERON RESTAURANT REPORTED HEARING A LOUD BANG – DEAD STARLING WAS FOUND AT

THE BASE OF A POLE NEAR THEM

Blue Heron

Dead Starling

Predicted Fault Location

IT IS QUESTIONABLE THAT THE STARLING CAUSED THIS FAULT

• Usually takes a bigger bird to cause a phase-to-phase fault

• Phase-to-phase fault current at location where starling was found did not match calculated fault current

• No burn marks from arcing were observed on the pole

A 10-15-15 FAULT WAS SIMILAR TO THIS ONE AND NO CAUSE WAS FOUND

(COMPARE TO SLIDE 36)

UG CABLE FAILUREL O C A T I O N P R E D I C T I O N G O O D

F L T I C O N T R I B U T I O N F R O M M I L L M O T O R S

SCADA ALARMS

INTERROGATE FEEDER BREAKERS

• Form 6 Recloser Controls did not show anything in Sequence of Events Files

• But they did capture Oscillographic waveforms• The fault was on Circuit 63. The Form 6 on Ckt 63

showed two Oscillographic events• First Event:

CIRCUIT 63 – SECOND EVENTLINEMAN REFUSED THE RISER POLE

CIRCUIT 62 CONTRIBUTED FAULT CURRENT DUE TO LARGE MOTOR LOAD

• Note that current is going in the opposite direction as the current in Ckt 63

FROM PQ METER ON SUB BUSRMS VALUE OF FAULT CURRENT IS CLOSE TO WHAT THE FORM

6 SHOWS: 2165 A ON FORM 6, 2072 A ON NEXUSFAULT LASTED FOR 1.5 CYCLES = .0025 SEC

FAULT LOCATION PREDICTION NOT FAR OFF

Fault on UG Cable

SYNERGI PROTECTION STUDY PREDICTS MAX SLG FAULT CURRENT TO BE 2292 A AT

THIS LOCATION

30 A FUSE SHOULD BLOW IN .019 SEC. AT 2165 AMPS. 1.5 CYCLES = .025 SEC.

QUESTIONS?G A I L S H A W

G S H A W @ T P U D . O R G