Ofil's Daytime Corona Camera

Ofil’s Daytime Corona Cameras

Daytime
Safety
Economic
Routine
corona cannot be seen during daytime

Corona – what is it?
We refer to the glow around a conductor or insulator or any high voltage electrical hardware as corona
Corona is caused by ionization of gas, where electrons that have gained energy from the local e-field revert to their original state and release light/energy mostlyin the UV range
A critical value of e-field (~24Kv/Cm) is needed to induce the local corona discharge
Local – it is around its source because the dielectric material does not allow ionization to propagate and the e-field decays rapidly with distance

Corona – why bother?
The reliability of high voltage power system is related to corona discharge parameter on a component level
Because
Corona causes insulation deterioration and to components degradation and to audio noise and radio interference
All power system components should be tested to verify that this parameter is controlled

Corona triggers degradation due to
Ultra Violet Radiation. Polymer material is susceptible to degradation due to UV more than to solar radiation
Ozone (O3) – Ozone is a byproduct of corona discharge. Ozone attacks materials such rubber, gaskets and seals
Acids – both organic (oxalic) and inorganic (nitric)Moisture in combination with contamination and corona create acid. Acid on polymers are active degradation factors
Mechanical attack– repeated corona bombardment drills holes in the polymeric substance.

Corona camera for daytime
Principle:
Bi-Spectral UV-Visible
Input: UV radiation – unseen by human eye + Visible view of the background
Output Visible representation of the unseen UV overlaid on the background

The spectrum: UVc is in the solar blind
UV
IR
120
C
B
A
10
100
8
80
Solar Radiation (µW/cm2/nm )
6
Filter Transmission (%)
60
4
40
2
20
200
300
400
500
600
700
800
900
1000
Wave length (nm)
visible range
corona

Bi Spectral imaging
250 kV
Combined mode
Visible mode
UV mode

Examples - Transmission
Transmission - BN

Examples - distribution
Pinpoint corona sources
13.4kV

Examples - substation

Examples - switchgear

Examples - motors

BenefitsofOfil’sCoronaCameras
Non-destructive (NDT) Corona Cameras allows you to:
Make daytime Inspection
Remote sensing
Detect Corona and UV events
Locate and pinpoint Corona
Measure UV events
Record each corona source
Create a PdM for Cost Effective purposes

Platforms
Aerial
Hand held for on foot patrol
Vehicle mounted
Compact handy hand held

Range of products
DayCor ®family
Sueprb
Ranger
Rail
Rom
ROMpact
UVolle
UVolle-Vi
UVolle-S
CITI – Corona Inspection Training Institutewww.citi-training.com

www.ofilsystems.com
Thanks.

Ofil's Daytime Corona Camera

by ofilsystems on Oct 02, 2011

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Ofil’s Daytime Corona Camera — Presentation Transcript