Comparative analysis of the method of insulation condition monitoring by ultraviolet radiation of surface partial discharges

Relevance . Unreasonable overhead power line outages are typically associated with flashover of line insulation due to contamination and moisture. Partial discharges on the insulation surface are fairly reliable indicators of dangerous levels of contamination and can be detected in a variety of ways. Remote non-invasive methods have become more popular for preventive control of the characteristics of surface partial discharges (SPD), they are based on the registration of acoustic and electromagnetic signals of various partial frequency ranges, as well as optical radiation in the infrared (IR) and ultraviolet (UV) parts of the spectrum. Daytime UV flaw detectors are considered promising for the realization of UV-inspection, they are also known by other names: UV cameras, UV visualizers, UV scanners, etc. These devices register corona radiation and surface partial discharges in the range of 240-280 nm and can be used in the daytime due to light filters cutting off solar radiation. Currently clear relationships between the characteristics of discharge processes and the degree of contamination of the insulation and its moisture-discharge characteristics have not been obtained even in laboratory studies. Of course, the complexity of the processes plays a determining role in that, but insufficient knowledge of the properties of the equipment and the influence of external factors contribute on the UV-inspection results. Purpose . To investigate the transmission characteristics of several types of UV flaw detectors and to evaluate the influence of the propagation ambience on UV-inspection results. Restrictions on the range of equipment settings and on the conditions for conducting UV-inspection in the field should be formulated based on the research results. Methods . Experimental research methods were used both in laboratory conditions and in the process of UV-inspection of real objects to solve the tasks. Results . Relationships between the readings of the photon counter and the area of UV-radiation from the input gain of UV flaw detectors have been experimentally established. Double impact of the effect of water vapors and dust particles on the result of recording the intensity of discharges was revealed. The practical application of the obtained results in ultraviolet inspection makes it possible to improve the diagnostic process, thereby increasing the reliability of electrical devices.