Comparison of AC Flashover Performance of Snow-Accreted Insulators Under Natural and Artificial Simulation Environments

Abstract

The research and exploration on snow-accreted insulators have been performed in an artificial climate chamber. However, the differences in the distribution, density and compactness of snow accretion under natural and artificial simulation environments cause the flashover mechanism of snowcovered insulators to remain poorly understood. In the present work, a series of flashover tests were carried out on snow-coated glass and silicone rubber insulators in the climate chamber and at Xuefeng Mountain Natural Icing Test Base. The discrepancies in the electrical performance and flashover process of snowcovered insulators under two test environments were compared and analyzed. Results show that the arc flashover gradient of snow accreted insulator at high altitude site is higher than that in the laboratory because of the differences of the environmental parameters. Affected by the adiabatic effect and capillary action of snow layer, within the range of the study the flashover gradient of insulators covered with snow increases with the increasing in the snow thickness. The calculation of various forces applied on arcs during its propagation demonstrates that when the arc current is less than 0.2 A, the local arcs develop along the snow surface of the insulators under the action of an electrostatic force. As the current increases beyond 0.2 A, the thermal buoyancy is predominant, thereby causing arcs to levitate from the insulator surface.

Influence of positive DC electric field on rime icing on the insulator and its experimental verification in the natural environment

“…The icing test in the natural environment is closer to the real icing situation than that in an artificial climate chamber [13, 27]. However, if natural precipitation is used to carry out the insulator icing test in the field, not only the test period is long but also the data obtained are not comparable due to differences in the environmental parameters.…”

Simulation calculation of 3D electric field and natural flashover analysis of ice‐covered silicone rubber insulator

“…Ice accretion on the surface of insulator is one of the key factors affecting the secure and stable operation of transmission lines. The degradation of electrical performance of the insulators caused by icing and even large-scale blackouts have been reported at home and abroad [1][2][3]. In January and February of 2008, disastrous ice and snow storm severely damaged of China grid in 14 provinces, with direct economic losses more than $16 billion [1].…”

On the Combination of Natural Environment Protection and Ethnic Development

“…Some scholars believe that the Chinese people's idea of "valuing economy and ignoring environment" is deeply rooted. Some scholars have proposed to integrate ecological civilization construction into economic and social development [5,6]. He pointed out that human beings should take people first as the principle, regard the ecological environment as a kind of resource rather than a cost, adhere to the scientific and rational use of resources and the environment, and give consideration to both immediate and long-term interests, so as to maximize the development and protection of natural resources.…”