DayCor® TechnologyDistribution

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

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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.• Wood Pole Fires • 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 at the right time

Corona Spot The outcome

Polymer Termination - 33KVPolymer Termination - 33KV

Physical damaged to componentPhysical damaged to component

Left string- Outcome Right string - Outcome

Corona spots

Cracks on 11kv insulatorCracks on 11kv insulator

Cement problem indication -11kvCement problem indication -11kv

Wood Pole FireWood Pole Fire

The leakage currents can generate enough localized heat to ignite the wood at the point of contact between wood and metal surfaces and start a pole fire

Insulators near or at the end of their service life can cause to pole fire

25kv

Audio noise - few reasonsAudio noise - few reasons

It indicates:• Possible Faults• Sealing defects• Shorted bells• Gap discharge • Loose hardware• Contamination• Corrosion or erosion• Bad ground connections

Corona is a concern because:Corona is a concern because:

Possible FaultsPossible Faults“This is not normally a serious issue but the broken wire was running down the side of the insulator, therefore reducing the insulating value from 6 sheds down to just one. The cause of there intermittent fault over 12 months has now been found in just 2 hours with the use of the corona camera"

22kV

Possible reasons

• Flash burn on the top shed from lightning

• Slight fracture on pin hole defect

33kv

Possible FaultsPossible Faults

Possible FaultsPossible Faults

Corona on the connection between the bushing and the capacitor.

Losing Energy it to lose Money !

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.

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Sealing DefectsSealing Defects

Shorted BellsShorted Bells

Gap dischargeGap discharge

ContaminationContaminationagricultural pollutionSalt contamination Agricultural pollution

Polluted conductor

Corrosion - ErosionCorrosion - Erosion

Bad ground connections-22kv insulatorBad ground connections-22kv insulator

Switchgear Switchgear

Corona

Corona

Corona

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

Equipment

broken

Outage

Potential Failure

C

Medium Counting Rate

Failure ProcessFailure Process

Failure starts here

LowCounting Rate

B

Equipment atNormal conditions

NoCorona

A

“…Attempting to measure and trend levels of observedultrasonic activity and trying to relate them to the potentialseriousness of surface partial discharge or end of life is notvalid and could potentially lead to misleading conclusions…”

“Testing Distribution Switchgear for Partial Dischargein the Laboratory and the Field”, by EA Technology, IEEE2008

UltrasonicUltrasonic