Assessment of the degree of contamination of insulation by the radiation spectrum of surface partial discharges

Unplanned overhead power line outages are typically associated with flashover of line insulation due to contamination and moisture. Powerful partial discharges on the insulation surface (SPD) can serve as a precursor to flashover. They can be detected by various remote methods: organoleptic (detection of discharges by visual and sound inspections), acoustic (ultrasonic signal recorders), electromagnetic (registration of emissions in the microwave and UHF ranges). The popularity of the introduction of optical methods of preventive control of equipment based on two fundamentally different physical principles is raising. Thermal imaging inspection of equipment radiation in the infrared (IR) region of the spectrum reveals local overheating of structural elements of equipment and is most effective for detecting defects in current-carrying parts and contact connections, cooling systems, etc. UV-inspection (UVI) is based on the detection of electrical discharge processes and it is most effective in detecting various kinds of defects in fittings and external insulating structures of high-voltage equipment. Solar-blind UV cameras are considered promising for the realization of UVI. However, the use of UV inspection for the assessment of external insulation contamination is still limited due to complex interpretation of inspection results and insufficient consideration of the influence of external factors and device settings. PURPOSE. To investigate the changes in the emission spectrum of the SPD with the change in the conductivity of the contamination layer at a constant value of the test voltage. Based on the research results, formulate principles for remote qualitative assessment of the contamination degree of external insulation of power lines and substation equipment based on a quantitative relationship. METHODS. High-voltage tests of insulators with different degrees of contamination in a fog chamber with registration of SPD by UV camera "Filin 6" with a special spectro-dispersing filter on the input lens were carried out to solve the set tasks. RESULTS. Designs of spectro-dispersing filters for lenticular and mirror-lens lenses are proposed. The spectral sensitivities of registration at joint operation of a spectrodispersing light filter and a multi-alkaline photocathode of an electron-optical converter were determined. Possible changes in transmittance windows for specific pollutants are suggested. The empirical dependence between the changes in the SPD emission spectrum and the conductivity of the surface contamination layer was obtained after processing the discharge emission patterns on the polymer post insulator. The developed methodology enables remote noninvasive qualitative assessment of contamination levels on high-voltage external insulation.

1. Hampton, B. F. (1964). Flashover mechanism of polluted insulation. 111(5), 985–990. https://doi.org/10.1049/PIEE.1964.0155

2. Rizk, F.A.M. (1981) Mathematical Models for Pollution Flashover. Electra, 78, 71-103.

3. CIGRE Task Force 33.04.01 (2000). Polluted Insulators: A Review of Current Knowledge. CIGRE Publication, No. 158.

4. IEEE Working Group on Insulator Contamination, Lightning and Insulator Subcommittee (1979). Application of Insulators in Contaminated Environment. IEEE Transactions on Power Apparatus and Systems, 98(5), 1676--1695.

5. Vladimirskii L.L. Fundamentals of the choice of external insulation of overhead power transmission lines based on the results of field studies in areas with soil, marine and industrial pollution // Izvestiya NTC Edinoj energeticheskoj sistemy. – 2025. – № 1(92). – С. 121-140. – EDN KMDOER.

6. Salem A. A. et al., "Pollution Flashover Under Different Contamination Profiles on High Voltage Insulator: Numerical and Experiment Investigation," in IEEE Access, vol. 9, pp. 3780037812, 2021, doi: 10.1109/ACCESS.2021.3063201.

7. Maraaba, L.; Al-Soufi, K.; Ssennoga, T.; Memon, A.M.; Worku, M.Y.; Alhems, L.M. Contamination Level Monitoring Techniques for High-Voltage Insulators: A Review. Energies 2022, 15, 7656. https://doi.org/10.3390/en15207656J.

8. J. He and R. S. Gorur, "Flashover of insulators in a wet environment," in IEEE Transactions on Dielectrics and Electrical Insulation, vol. 24, no. 2, pp. 1038-1044, April 2017, doi: 10.1109/TDEI.2017.005795

9. Vladimirskiy, L. L., & Solomonic, E. A. (2015). Development of Methods for Selecting External Insulation for High-Voltage Installations. Electric Stations, 12, 23--36.

10. Golenishchev-Kutuzov VA, Golenishchev-Kutuzov AV., Semenikov AV, Mardanov GD., Kalimullin RI., Ivanov DA. Generation of critical acoustic pulses in high-voltage insulators due to induced fields of partial discharges. Power engineering: research, equipment, technology. 2023; 25 (1): 154-165. doi:10.30724/1998-9903-2023-25-1-154-165.

11. Golenishchev-Kutuzov A.V., Akhmetvaleeva L.V., Enikeeva G.R., Ivanov D.A., Semennikov A.V., Mardanov G.D. Remote testing for defects in service high-voltage insalators. Power engineering: research, equipment, technology. 2020;22(2):117-127. (In Russ.) https://doi.org/10.30724/1998-9903-2020-22-1-117-127

12. Ivanov, D.A.; Sadykov, M.F.; Yaroslavsky, D.A.; Golenishchev-Kutuzov, A.V.; Galieva, T.G. Non-Contact Methods for High-Voltage Insulation Equipment Diagnosis during Operation. Energies 2021, 14, 5670. https://doi.org/10.3390/en14185670

13. Zaripov D.K., Zakirov D.F., Tarasov B.P., Mironova E.A., Nasibullin R.A. Experimental study of the possibility of detecting contamination of high-voltage insulators with the help of a thermal imager. Power engineering: research, equipment, technology. 2024; 26 (6): 5-19. doi:10.30724/1998-9903-2024-26-6-5-19

14. Zaripov D.K., Nasibullin R.A., Zakirov D.F., Zakharov A.V. Study of operation of a polymer insulator under uniform and non-uniform contamination. Power engineering: research, equipment, technology. 2023;25(5):20-29. (In Russ.) https://doi.org/10.30724/1998-9903-202325-5-20-29

15. Ovsyannikov A.G., Zharich D.S., Shvets N.A. Comparative analysis of the method of insulation condition monitoring by ultraviolet radiation of surface partial discharges. Power engineering: research, equipment, technology. 2025; 27 (4): 82-93. doi: 10.30724/1998-99032025-27-4-82-93.

16. P. Blackmore and D. Birtwhistle, "Surface discharges on polymeric insulator shed surfaces," in IEEE Transactions on Dielectrics and Electrical Insulation, vol. 4, no. 2, pp. 210-217, April 1997, doi:10.1109/94.595248.

17. L. Jin, D. Ma, Z. Yuan, G. Zhou and S. Han, "Evaluation of Surface Discharge of Polluted Insulator Based on Optical Emission Spectroscopy Measurements," in IEEE Transactions on Dielectrics and Electrical Insulation, vol. 31, no. 1, pp. 350-357, Feb. 2024, doi: 10.1109/TDEI.2023.3300258.

18. А. Ovsyannikov, V. Borovitsky. Рossible reasons of transmission line unexplained outages. Proceedings of the 18th International Symposium on High Voltages, Seoul, Korea. Paper PG-08, 2295--2298.

19. Efimov E.N., Timashova L.V., Yasinskaya N.V. Causes and Nature of Damage to Components of 110-750 kV Overhead Transmission Lines in 1997-2007 // Energy of the Unified Grid. — 2012. — № 5(5). — P. 32-41.