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Published byHoward Walker Modified over 9 years ago
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Ofil’s proprietary material Cannot be used without Ofil's explicit permission
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Ofil’s proprietary Material | 2011 Partial Discharge and the Corona Phenomenon Solar Blind Imaging Corona Inspection as a PDM tool in hand Faults Indications Methodology
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Ofil’s proprietary Material | 2011 Detect PD corona & arcing - in daylight Diagnostic tool Condition monitoring of critical components Perform predictive maintenance
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Trigger localized high e-fields that exceed a critical value 20-30 kV/cm Generates Audio noise Corrosive materials (O 3, NO - ) Radio and TV interferences UV - corona
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E field e e + e e + e e e + -V e UV Ph In the presence of a strong E-field Free electrons accelerate Collide with air molecules and ionize them Additional electrons are released Photons are released with recombination Procedure repeats itself
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Ozone blocks Solar UV Signals
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Goal: Collect UV events & superimpose Imaging “Black Box” input - sceneryoutput - screen
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Ofil’s proprietary material Cannot be used without Ofil's explicit permission
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External – surface Line of sight Voltage dependent Any weather conditions Indicator & Actor Fault early stage detection
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Corrosion and erosion Pitted cement Hydrophobicity compromise RFI/TVI
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3. Lineman from EMC takes down the faulty arrestor 1. Corona during hazy day 2. Camera depicts the exact corona arcing location RFI/TVI Case 1: A US Government Licensed Radio Amateur Operator: The receiving equipment was reading a noise level of some 30 dB over S9 (Signal strength is measured in S-units from S1 to S9) and the noise blanking system of the receiving equipment could not eliminate the noise.
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Case 2: USA 1.RFI at FAA Control Tower during wet weather 2. The source: Bad grounding on 4.16kV, 12.47kV, 115kV insulators Case 3: Czech Republic 1.RFI at Czech Radio Telecomm Authority experienced TVI 2. The source: Pin of a ceramic insulator was wrongly installed
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Tracking & loss of hydrophobicity
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Brittle fracture: corona cameras can clearly show surface discharge that exists on insulators with housing imperfections in order to avoid catastrophic failure.
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Faulty designs Faulty installations Poor material Existing processes
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No corona ring Grading ring installed backwards
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Cracked insulator Wrong design
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AN, RI, TVI concern? Events per Minute Can it be damaged by corona? Corona- where? Critical component? Material type Critical location? Corona intensity? No 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
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THANK YOU
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