The umbrella shape of composite insulator has a great influence on its electric field dispersion, so the transformation of composite insulator umbrella shape is stopped, which can improve the surface electric field dispersion of glass insulator under icing state; Compared with the electric field dispersion of double umbrella and four umbrella insulators, four umbrella composite insulators have obvious advantages.
The large umbrella diameter and the large umbrella spacing have an obvious influence on the electric field dispersion of the composite insulator under the same icing state. With the increase of the umbrella diameter, the surface electric field dispersion of the composite insulator under the same icing state is more average, and the high field strength also decreases with the increase of the umbrella diameter. However, when the umbrella diameter of composite insulator exceeds 245mm, this trend slows down. In order to improve the electrical performance of insulator under icing state and ensure the self-cleaning of insulator at the same time.
The diameter of the large umbrella of the recommended multiple platform insulator shall not exceed 245mmj. With the increase of the spacing of the large umbrella, the expansion field strength of the composite insulator under the same icing state decreases, and there is no obvious saturation trend. However, in order not to increase the structural height of the insulator, at the same time, adhere to the umbrella spacing / 'the extension of the umbrella is above I, and the spacing of the recommended large umbrella is below 140mm. Because the middle umbrella and small umbrella of composite insulator are maintained by the large umbrella, the umbrella diameter has little effect on the surface potential distribution of the whole composite insulator.
The grading ring of composite insulator has a certain influence on the distribution of external field strength under icing. When its lifting distance is o - 5cm, it can ensure that the large field strength of the gap near the ice edge at the left of the high-voltage end and the high-voltage end can reach a better coordination. At the same time, in order to ensure that the lifting distance of the grading ring of insulator does not reduce its arc interval, so as to reduce the impact flashover voltage, the vertical lifting distance is taken as OCM
