daycor ® technology
DESCRIPTION
DayCor ® Technology. Transmission. DayCor ® Technology. DayCor® Technology is used to detect Corona Particle Discharge and Arcing on electric grid components. It offers you: - PowerPoint PPT PresentationTRANSCRIPT
DayCor® TechnologyTransmission
DayCor® Technology is used to detect Corona Particle Discharge and Arcing
on electric grid components.
It offers you:
• Early warnings of potential future failures.• Pinpointing & Visualizing the corona effect. • Decision ability to determines the health of your critical systems components• Prioritize your particle discharge maintenance challenges • Day time work DayCor® Technology saves you by avoiding costly unscheduled outages and failures
DayCorDayCor®® Technology Technology
E field e
e
+
e
e
+
e
e
e
+
--V V ee
UV Ph
UV Ph
UV Ph
Corona is a luminous partial discharge due air ionization. The DayCor® camera pinpoints the exact source’s location by visualizing the UV photons, coming out of it.
Corona EffectCorona Effect
Corona Source Free Electron, coming out from the source
Natural Air molecule
UV Photon
Combined mode
Visible only display
UV only mode
Bi-Spectral ImagingBi-Spectral Imaging
Pinpointing the exact corona’s location
UV-IR complimentary technologiesUV-IR complimentary technologies
No corona on IR picture Corona spots using UV technology
Live End Corona
Dead End Corona
It causes:• Degradation of polymer (NCI) insulators• Ceramic Insulator Defects • Physical damage to component.• Cracks the cement of pins and metal caps of porcelain
insulators.• Audio noise (AN)
Corona is a concern because:Corona is a concern because:
Degradation of polymer (NCI) insulatorsDegradation of polymer (NCI) insulators
To get to that point is to waste your time & moneyDetect this failure in advance to take the right action on time
Corona Spot The outcome
Ceramic insulators defects Ceramic insulators defects
Component: 138 kV Insulator StringProblem: First Insulator bell is damaged
Physical damaged to componentPhysical damaged to component
Left string- Outcome Right string - Outcome
Corona spots
Crack in cement and metal caps of porcelain insulatorsCrack in cement and metal caps of porcelain insulators
Corona Spot Outcome
Audio noise - few reasonsAudio noise - few reasons
• Component: Connector on 138 kV Transformer Bushing• Problem: Sharp edges on connector cause radio and TV
interference
Audio noise - few reasonsAudio noise - few reasons
It indicates:• Possible Faults• Sealing defects• Shorted bells• Gap discharge • Loose hardware• Contamination• Corrosion or erosion• Broken Strands• Bad ground connections
Corona is a concern because:Corona is a concern because:
Possible FaultsPossible Faults
Corona on the connection between the bushing and the capacitor.
Losing Energy it to lose Money !
138Kv
Possible FaultsPossible Faults
Leaking Current
Dead End Corona
Sealing DefectsSealing Defects
Indication The problem
Hollow core insulator. The core should be sealed at the bottom with a cork/rubberplug. The cork/rubber plug was cracked compromising the seal. Without the seal, moist air was introduced into the hollow core. The dielectric properties of the insulator were changed affecting the electric field.The condition would eventually lead to insulator failure.
Ameren
play
Sealing DefectsSealing Defects
Shorted BellsShorted Bells
When you see corona at the middle of the insulator and the rest of it is clean check for short bells case
Pic 1: Corona on the 4th bell.
Pic 2: Porcelain bells were replaced by glass bells due to being shorted
1
2
Gap DischargeGap Discharge
Loose hardwareLoose hardware
ContaminationContaminationagricultural pollutionSalt contamination Agricultural pollution
Polluted conductor
Corrosion or ErosionCorrosion or Erosion
Corona spot due to erosion
Broken StrandsBroken Strands
Bad ground connectionsBad ground connections
AN, RI, TVI concern?
Decision ChartDecision Chart
Photons per Minute Can it
be damaged by corona?
Corona- where?
Criticalcomponent?
Material typeCritical location?
Corona intensity?
No
No
No
Yes
Yes
Yes
High> 5000
1000<Medium<5000 Low<1000
Monitor for additional signs
Schedule repair or replacement
Repair or replace ASAP
No
Yes
Repair or replace ASAP
Condition
D
Equipment fails to perform as expected
Functionally failed
High CountingRate
Equipmentbroken
Outage
Potential Failure
C
Medium Counting Rate
Failure ProcessFailure Process
Failure starts here
LowCounting Rate
B
Equipment atNormal conditions
NoCorona
A