Are there any methods to prevent fouling on insulators?
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Currently, the only method used to prevent contamination on insulators is cleaning; synthetic insulators, on the other hand, are not cleaned. Flashover due to contamination still occurs in areas with high pollution levels, and there is no effective solution for this problem
Anti-fouling coatings can be considered.
What types of coatings can be used?
Regarding the anti-fouling issue, regular dust removal can be carried out; high-pressure motor cleaning agents can also be used for oil removal:
The insulators designed using the new method feature a metal ring with a silicone rubber coating on its outer surface, attached to the iron cap of conventional insulators. The inner diameter of this metal ring must match the outer diameter of the iron cap to ensure a tight fit during installation； The outer diameter is approximately two-thirds of the insulator disc diameter. The metal torus can be either flat or have a curvature that is essentially the same as that of the upper surface of the insulator, depending on the shape of the insulator’s upper surface, the manufacturing process, the cost of modification, and the extent of the improvement achieved. Generally speaking, a toroidal shape that matches the upper surface shape of the insulator is better suited to improving the electric field distribution, whereas a uniform planar shape facilitates manufacturing. The manufacturing and assembly process of the new type of insulator is as follows: First, a metal sheet with a thickness of about 2 mm is processed into ring-shaped pieces with the desired dimensions and shape. Then, using appropriate molds, silicone rubber with a thickness of around 2 mm is vulcanized onto the upper and lower surfaces as well as the outer sides of these metal rings, while keeping the inner metal surface clean. Then this component is assembled onto the iron cap; during the assembly process, in addition to ensuring a secure fit, it is also necessary to guarantee good electrical contact between the inner surface of the metal ring and the iron cap. A layer of insulating glue should be applied at the joint between the silicone rubber and the insulating porcelain on the outside of the metal ring sheet, to prevent corona and flashover from occurring there. The specific installation location of the additional components depends on the type of insulator; the general principle is that the location should be appropriate: it must not be too close to the surface of the insulator, so as to avoid a too short distance between the outer edge of the ring and the insulator’s surface, which could lead to air breakdown ； It also shouldn’t be too far away, to prevent the effect of the metal rings in improving the electric field distribution from being weakened. This post was last edited by XJTZWKDPJ on 2007-12-11 11:56.]
It’s a creative idea from a friend; I’m not sure what tool was used for that Could you provide the trial results? Thank you!
In the case of glass or magnetic insulators, in areas with a pollution level of 4 or higher, it is necessary to install creepage skirts (three pieces for 110 kV) first, and then apply anti-fouling coatings. If synthetic insulators are used, the number of skirts should be increased, and it is advisable to use the upper limit value for the same voltage class.
Performance of the anti-pollution flashover coating: 1. Service life of 20 years. 2. Surface drying time of the coating is 20 minutes. 3. The voltage resistance against pollution-induced flashovers is increased by more than 2 times. 4. Its water-repellent property is grade 1, with a recovery time of about 12 hours. 5. Adhesion strength is grade 1. 6. Dielectric strength ranges from 32.3 to 34.2 KV/mm. 7. Resistance to electrical erosion is grade TMA 4.5. 8. Solid content is approximately 60%. 9. Flammability rating is FV-0. 10. Tear strength is 19.0 KN/M. 11. Shear strength is 2.372 Mpa. 12. Peeling strength in self-cleaning tests is 1.89 Kpa. 13. Under artificial accelerated aging conditions at a voltage of 17.1 KV for 1700 hours, there is no current interruption, no signs of leakage, and no electrical erosion of the ceramic surface. The PRTV anti-pollution flashover coating contains nanoscale high-insulation reinforcing materials, which grant it high mechanical strength and adhesion; it can withstand the erosion caused by strong winds and sand (e.g., in areas exposed to wind, or on electric locomotives). It meets the requirements for equipment maintenance and handling. In cases of particularly severe contamination (e.g., when the coating is covered by a large amount of dusty contaminants, making it difficult for the water-repellent properties to reach the outer layer of the contamination), it is possible to carry out necessary water washing or cleaning. The mechanical properties of the PRTV coating are comparable to those of the insulating material used in umbrella-shaped covers of synthetic insulators. The polysiloxanes, which are the main chemical components of silicone rubber in PRTV permanent anti-pollution flashover coatings, are inherently hydrophobic. However, to meet the electrical requirements related to creepage resistance and arc quenching for temperature reduction, arc-suppressing agents must be added to the formulation. Our company uses arc-suppressing agents that we have developed ourselves, while in other RTV coatings, such agents are aluminum oxide and similar substances. Therefore, our PRTV permanent coatings maintain a high level of overall performance; their hydrophobicity remains on par with that of conventional RTV coatings, and in terms of the consistency and durability of this hydrophobicity, they are comparable to the materials used in the insulator skirt coatings. Performance features: Suitable for a wide range of pollution types and applications. It exhibits excellent water repellency and water-repellent migration properties, which can significantly increase the pollution flashover voltage. It boasts extremely strong adhesion and resistance to acid and alkali corrosion, making it suitable for the initial coating as well as re-coating on porcelain insulators and glass surfaces. Excellent self-cleaning ability; dirt on the surface of the coating can be easily washed away by rain or blown off by wind. High strength, resistant to aging, does not peel or crack. After the external insulation of electrical equipment is put into use, neither the preventive testing methods nor the test results are affected. http://www.jndzkj.cn/UploadFiles/2008418135943738.jpg http://www.jndzkj.cn/UploadFiles/200813154451487.jpg
There are many methods of electrocleaning available these days; you can check out a few cleaning companies