Study Of Insulator Discharge Detection Based On UV Imaging

Corona discharge can consume electrical energy，also produces electromagneticpulse to make interference on high-frequency and radio communications．Gas producedby corona discharge also causes corrosion of power transmission equipment surfaces,thereby reduces the life of the equipment．UV imaging has been widely used ondetecting discharge. It has the advantage of single method, convenient operation,rapidity，vividness, Intuition．However, many factors such as instruments, gain, distanceused during the experiment frequently lead to raise differences in UV discharge testresults.In this paper, the different types of insulators discharge was simulated in artificialclimate test chamber to analyze the influence of general factors such as instruments,gain, detection distance, wind speed, angle on UV detection. Studies have shown thatdifferent manufacturers and types of instrument have its own measurement of photonsand imaging characteristics. The number of photons increases as the gain is graduallyincreased, begin to decay after reaching extreme. This law is affected by the gain.Photon number and distance have a complex nonlinear relationship affected by the gain.Less than5m/s wind speed does not affect the results of UV detection. Results detectedby Ultraviolet imager from the front to the side are basically the same.This paper also studied insulator discharge UV imaging features under complexenvironmental conditions, revealed the UV imaging law and discharge mechanism atthe time of rain, contamination, icing. The discharge intensity of insulators incontamination conditions significantly was affected by humidity and contaminationunevenness，and corona onset voltage was lower. Insulator onset voltage also droped inthe rain. Insulators discharge point likely shifted in the rain state due to shape change ordisplacement of raindrop. The formation of rain curtain gathered insulator umbrellagroup edge caused electric field distortion and Arc formation. When the rain washeavy，the photon number detected was fewer. This is because the heavy rain blockedthe path of photons entering the lens. Iced insulators discharge was affected by the iceover. The heavier ice cover, the greater the probability of ice bridging. Insulatordischarge is divided into four stages including Halo effect, stable corona, brush discharge, arc discharge according to insulator discharge imaging features and thenumber of photons measured.Based on mathematical morphology method and image processing technology,Spot area is proposed to characterize intensity discharge as characteristic parameter andverify its feasibility.The results of this study have important reference value to improve the detection ofUV corona imaging procedures and practical application.