Xiao Lu^1,*, Chengling Jiang¹, Zhoujun Ma¹, Haitao Li², Yuexin Liu²

CMC-Computers, Materials & Continua, Vol.79, No.1, pp. 373-390, 2024, DOI:10.32604/cmc.2024.047469

Abstract Insulator defect detection plays a vital role in maintaining the secure operation of power systems. To address the issues of the difficulty of detecting small objects and missing objects due to the small scale, variable scale, and fuzzy edge morphology of insulator defects, we construct an insulator dataset with 1600 samples containing flashovers and breakages. Then a simple and effective surface defect detection method of power line insulators for difficult small objects is proposed. Firstly, a high-resolution feature map is introduced and a small object prediction layer is added so that the model can detect tiny objects. Secondly, a simplified… More >

Zhibo Song^1,*, Hao Yang¹, Wei Shen², Yixin Ren¹, Yawei Li³, Jianlong Ma¹

Energy Engineering, Vol.120, No.9, pp. 2097-2113, 2023, DOI:10.32604/ee.2023.029115

Abstract Pollution flashover is one of the major insulation accidents that can occur in modern power systems. If the local arc is not sufficiently elongated by the creepage distance, the flashover performance of the insulator will decrease. The insulator structure and equivalent salt deposition density (ESDD) are the main factors affecting the arc path and length. To investigate the forms of arc paths under different insulator structures and their influence on flashover characteristics, a platform for recording arc paths is established. This study presents a method to identify the pattern and distribution of insulator arc paths based on the effect of… More >

Yukun Lv, Zeze Chen^*, Quanzhi Ge, Qian Wang, Yazhao Zhang

Energy Engineering, Vol.120, No.2, pp. 483-499, 2023, DOI:10.32604/ee.2023.023649

Abstract To investigate the fouling characteristics of the composite insulator surface under the salt fog environment, the FXBW-110/120-2 composite insulator was taken as the research object. Based on the field-induced charge mechanism, the multi-physical field coupling software COMSOL was used to numerically simulate the fouling characteristics, explored the calculation method of ESDD, and demonstrated its rationality. Based on this method, the pollution characteristics of the composite insulator under the pollution fog environment were studied, and the influence of wind speed, droplet size, and voltage type on the pollution characteristics of the composite insulator was analyzed. The results showed that: with the… More > Graphic Abstract

Sihua Wang^1,2, Junjun Wang^1,2,*, Lijun Zhou^1,2, Long Chen^1,2, Lei Zhao^1,2

Energy Engineering, Vol.119, No.1, pp. 219-236, 2022, DOI:10.32604/EE.2022.016899

Abstract

Pollution flashover accidents occur frequently in railway OCS in saline-alkali areas. To accurately predict the pollution flashover voltage of insulators, a pollution flashover warning should be made in advance. According to the operating environment of insulators along the Qinghai-Tibet railway, the pollution flashover experiments were designed for the cantilever composite insulator FQBG-25/12. Through the experiments, the flashover voltage under the influence of soluble contaminant density (SCD) of different pollution components, non-soluble deposit density (NSDD), temperature (T), and atmospheric pressure (P) was obtained. On this basis, the GA-BP neural network prediction model was established. P, SCD, NSDD, CaSO₄ mass fraction (w(CaSO₄)),… More >

Wei Zhao¹, Miao Jiang², Jun Dong¹, Lee Li^2,*

Energy Engineering, Vol.118, No.6, pp. 1755-1766, 2021, DOI:10.32604/EE.2021.015467

Abstract In recent years, more and more high-voltage overhead transmission lines were built passing through the karst regions in southwestern China. This type of special landform seems to have an adverse effect on the aging of the sheds of the line suspension composite insulators, which may lead to unexpected flashover and line tripping. In order to find out the particularity of the aging characteristics of insulators operating in the karst regions, samples in operation were selected from both the karst regions and the flatlands. Hydrophobicity, amount of surface contamination, and contaminant composition of the sheds were studied, then a comparison of… More >

Yukun Lv, Yuechi Wang^*, Jiawen Wang

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 971-987, 2021, DOI:10.32604/fdmp.2021.016602

Abstract When separated water droplets condense on the surface of a composite insulator, the electrical field on the insulator surface is distorted. In turn, such distortions change the trajectories of pollution particles. In this study, the COMSOL software is used to simulate such a process for the FXBW4-10/100 composite insulator with or without water droplets condensation under a 10 kV DC voltage. The influence of the wind speed and particles concentration on the contamination characteristics of the considered 110 kV insulator is analyzed. The results show that: 1) in the presence of water droplets on the insulator surface, the ratio of… More >

Ali Salem¹, Rahisham Abd-Rahman¹, Waheed Ghanem^2,*, Samir Al-Gailani^3,4, Salem Al-Ameri¹

CMC-Computers, Materials & Continua, Vol.68, No.3, pp. 3755-3771, 2021, DOI:10.32604/cmc.2021.016988

Abstract

This paper aims to assess the effect of dry band location of contaminated porcelain insulators under various flashover voltages due to humidity. Four locations of dry bands are proposed to be tested under different severity of contamination artificially produce using salt deposit density (SDD) sprayed on an insulator. Laboratory tests of polluted insulators under proposed scenarios have been conducted. The flashover voltage of clean insulators has been identified as a reference value to analyze the effect of contamination distribution and its severity. The dry band dimension has been taken into consideration in experimental tests. The flashover voltage has been predicted… More >

Yukun Lv, Yuechi Wang^*, Jiawen Wang, Jing Wang, Jiaxi Yang

Energy Engineering, Vol.118, No.3, pp. 631-642, 2021, DOI:10.32604/EE.2021.014578

Abstract In recent years, more than 50% of the cities in the inland area of our country have suffered from moderate pollution. It can affect the distribution of electric field along the surface of insulator and the pollution characteristics of its surface area, even endanger the safe operation of transmission lines. This paper takes the XSP-160 porcelain three umbrella insulator under the action of 0–±30 kV DC voltage as the research object, and establishes the physical model of the insulator; uses COMSOL software to simulate the electric field of the insulator. The comparison with the results of the wind tunnel test… More >

M. Kumosa¹

Structural Durability & Health Monitoring, Vol.3, No.1, pp. 35-50, 2007, DOI:10.3970/sdhm.2007.003.035

Abstract This paper deals with the structural integrity and durability of suspension composite (non-ceramic, polymer) insulators widely used in power transmission systems around the world. Under certain conditions, the insulators can fail in-service both electrically and mechanically resulting in the drop of energized transmission lines and power outages. In this work, predominantly mechanical failures of the insulators are discussed. In particular, the most important characteristics of a catastrophic failure process called brittle fracture are described. Subsequently, two examples of insulator failures by brittle fracture are shown and their causes explained. Finally, several recommendations on how to avoid brittle fracture as well… More >