Discharge Detection Method Of High Voltage Electrical Equipment Based On Ultraviolet Signal

Under the long-term effection of electric field, thermal field, mechanical stress, chemical corrosion and environmental conditions and other factors, the insulation performance of power plant high-voltage electrical equipment would gradually decline, which can form discharge phenomenon in certain conditions. Discharge will radiat utraviolet light signal, to detect the signal may realize the discharge of non-contact detection, so it has important theoretical significance and value of the works to detect insulation defects and to prevent accident in time in power system. In this paper, by experimental and theoretical studies of voltage electrical equipments surface discharge was studied in power plant, and the main work and achievement are as the followings:The mechanism of high-voltage equipment discharge optical radiation was analysed, A UV impulse detection system was established according to the characteristics of spectral distribution of discharge and the solar spectral distribution, corresponding hardware and software system was developped and the performance was tested as well. Testing results showed that the system has a good linearity and detection sensitivityIn this pape, the work principle and structure of solar blind UV camera was analysed, according to the imaging chareacteristic, a video analysis and digital image processing algorithm was induced to extract the facular area and diameter parameters, and they were used to uantitatify the UV imaging deteciotn result. The characteristics of the photon number and facular area changes with observation distance and gain for the rod-plate gap and power plants insulator hardware discharge were analysed. The related curve was obtained, which was explained by the principle of UV imageing.The relationship between the light impulse signal and electrical impulse signal is researched, which showed there was approximate linear relationship between them. However, in the period of arc discharge stage when impulses amplitude is the same, the light pulse signal amplitude is less than corona and spark discharge. The relationship of the facular area and electrical impulse signal is researched. The changing characteristics of different discharge intensity and different gain with distance was analysed. In this paper, the method to estimate the observation distance with the visible channel image information is presented, and corresponding formula was also put forward. then the electrical impulse signal intensity estimation method was preseted based on ANFIS algorithm.Research insulation in good condition and the aging high-voltage electrical equipment stator winding in the withstand voltage test of the UV images and UV pulse signal characteristics, discharge characteristics, caused by the low insulator fittings and sheds of the insulator in the dry and wet circumstances.discharge optical signal characteristics, to study the UV signal characteristics of the discharge of dirty porcelain post insulators, studies show that under certain conditions, the UV signal can be effectively found that the insulation defects.The UV impulse and UV imaging characteristics of the stator winding under the withstanding high voltage testing experiment was researched, while the insulation was in good and the aging conditions. Discharge UV characteristics caused by the low value insulator, end fittings and sheds of the insulator in the dry and wet circumstances were also researched. UV signal characteristics of polluted porcelain post insulators discharge were studied. Research results show that under certain conditions, to detect UV signal charicter is an effective method to find high voltage equipment defects.