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

Abstract

The effects of uneven icing, number of icicles, inclination angle of icicle, ice pallets and arc ignition on the electric field are ignored for the two-dimensional axisymmetric model of ice-covered insulator. Therefore, a 3D simulation model was developed in this paper. The average electric field strength of air gap (E av ) and maximum field strength of icicle tip (E max ) were determined to characterize the influence of various factors on the electric field distortion degree. The results show that compared with the insulator without ice and with a dry ice, the supply voltage is almost entirely applied to all icicle air gaps for a wet ice-covered insulator. E av is independent of icicle diameter and icicle number but increases with the increment of icicle length and icicle inclination angle. E max raises with the increase of icicle length, icicle number, icicle inclination angle and icicle diameter. As the source of electric field distortion, the ice pallets on the surface of the sheds rise the field strength of air gap. Based on the simulation analysis and natural icing test, the applied voltage is redistributed in the remaining air gaps when an arc occurs in the gap near the high-voltage terminal, thereby causing the subsequent flashover.

Optimized hybrid YOLOu‐Quasi‐ProtoPNet for insulators classification

“…The proposed personalized ultra-large version of YOLOv5, named YOLOv5u emerged from the consideration that larger models have better mAP results in preliminary experiments presented by Ultralytics. 1 A progression in classification capability is observed when increasing network size, for this reason, a model larger than YOLOv5x seems promising, with YOLOv5x having the best results compared to other models with fewer parameters such as YOLOv5n, YOLOv5s, YOLOv5m, and YOLOv5l. The results of these models are based on a pretrained dataset using the common objects in context (COCO) [55].…”

“…Insulators in the transmission lines are components responsible for supporting the electrical power grid and isolating the electrical potential [1]. When there is an accumulation of contamination on the surface of these components, electrical discharges may occur [2][3][4].…”