Research on Image Recognition Method of Icicle Length and Bridging State on Power Insulators

Zhu, Youwen; Liu, Cheng; Huang, Xinbo; Zhang, Ye; Tian, Yousheng

doi:10.1109/access.2019.2958177

Cited by 10 publications

(7 citation statements)

References 23 publications

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“…A strong field area is available at the end of the ice ridges, and it is in the area that the phenomenon of discharge will occur. When there are water droplets hanging at the end of the ice ridge, the possibility of discharge at the end of the ice ridge will witness a sharp increase due to the water droplets with high conductivity, and the probability of flashover will see an increase as well [16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Effects of Static Icing on Flashover Characteristics of High-Speed Train Roof Insulators

Zhang

et al. 2022

Coatings

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To study the icing flashover characteristics displayed by insulators on the roof of a high-speed train at a low-speed or static state, an environment with a low temperature and high humidity is established in the artificial climate chamber to carry out the icing flashover test of composite insulator under a static state. The results of the study indicate the presence of ice ridges bridging the sheath at the edge of the sheath when the ambient wind speed is less than 2m/s. The arc appears firstly at the end of the ice ridge, and it is likely that the arc at the adjacent tip converges in the air and then further extends to the edge of the next sheath. The arc melts the ice ridges at the end and enables it to stick to the tip of the ice ridge in the form of water droplets, and therefore the existence of droplets results in the distortion of the electric field near them. Moreover, the elongation of droplets and the bridging of ice edges accelerate the process of flashover. The research results can offer a reference to the structural optimization design of anti-icing insulators for high-speed trains in the future.

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Section: Introductionmentioning

confidence: 99%

Effects of Static Icing on Flashover Characteristics of High-Speed Train Roof Insulators

Zhang

et al. 2022

Coatings

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“…As the temperature rises, under the combined action of solar radiation, airflow, leakage current and other factors, the surface of the icing layer will melt first, forming a water film (melted water on the rime icing surface will be absorbed by its own porous structure, forming sponge ice mixed with ice and water). And the surface contamination of the insulator and the conductive ions precipitating from the icing water will greatly weaken the insulation strength of the insulator, and the flashover risk is the greatest during this period [2][3][4][5]. Therefore, it is of theoretical value and practical engineering significance to carry out research on the natural melting model of iced insulator and the evaluation of icing flashover probability to realize the prediction and early warning of icing flashover based on meteorological forecasts and meteorological data collected from local weather bureaus and field test.…”

Section: Introductionmentioning

confidence: 99%

Study on natural ice-melting process of insulator by thermodynamic analysis

et al. 2022

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Insulator flashover caused by atmospheric icing is a serious accident with high frequency. The flashover risk on insulators during ice-melting process is higher than that during icing accretion process. Therefore, it is of great theoretical significances and engineering value to carry out research on risk prediction methods of ice-melting flashover on insulators. Firstly, this paper presents a thermal balance equation of the iced insulator surface for icing natural melting process and calculates the main influencing parameters of the ice-melting process by thermodynamic analysis. Secondly, this paper extracts the meteorological data from great numbers of on-site ice-melting flashover cases to calculate the meteorological condition with the highest flashover risk. On the basis of this, to judge the state of freezing or melting, a thermodynamic criterion of freezing and melting state is proposed, and the finite element analysis is applied to model iced and non-iced insulators, and the temperature distribution, the wall heat transfer coefficient distribution of the airflow field are analyzed. The results suggest that the local micrometeorological temperature and the heat transfer coefficient have the greatest impact on the ice-melting process of insulators. The structure of insulator will be changed by the covered ice, ended up to a cone-like structure which will weaken the influence of the vortex on the central leeward side. And the heat dissipation and melt characteristics of iced insulator will be quite different from that of non-iced insulator.

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“…The associate editor coordinating the review of this manuscript and approving it for publication was Boxue Du . mechanism [10]- [11], and flashover characteristics of the insulators [12]- [14]. Natural icing observation stations and test sites have been established [15]- [16], which helps in investigating power system icing.…”

Section: Introductionmentioning

confidence: 99%

Influence of Crystallization Effect During Icing Water Phase Transition on the Flashover Characteristics of Ice-Covered Insulators

Jiang

Yang

et al. 2020

IEEE Access

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The crystallization effect during the phase transition of icing water has a significant impact on the electrical performance of an ice-covered insulator. However, the spatial distribution of conductive ions in the ice layer remains poorly understood. In this study, the crystallization effect was confirmed through a condensation test of the potassium permanganate solution. The influence of freezing water conductivity, ice thickness and equivalent salt deposit density on the spatial distribution of conductive ions was determined by a triangular ice sample, wherein the effect on the flashover characteristics of ice-covered insulator was investigated. Results show that MnO − 4 migrates to the unfrozen area during freezing, thus accumulating on the droplet top. The conductivity of melted water on the exterior surface of an ice sample is considerably higher than that of icing water. The former can reach a maximum of 5.7 times the latter when the freezing water conductivity method is adopted. This value is 9.7 for a polluted ice sample. A highly conductive water film forms on the insulator surface because of the crystallization effect in the melting period, thereby improving the leakage current and reducing the residual ice resistance, which results in the decrease of flashover voltage.INDEX TERMS Crystallization effect, icing water, ice-covered insulator, leakage current, flashover voltage.

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Research on Image Recognition Method of Icicle Length and Bridging State on Power Insulators

Cited by 10 publications

References 23 publications

Effects of Static Icing on Flashover Characteristics of High-Speed Train Roof Insulators

Effects of Static Icing on Flashover Characteristics of High-Speed Train Roof Insulators

Study on natural ice-melting process of insulator by thermodynamic analysis

Influence of Crystallization Effect During Icing Water Phase Transition on the Flashover Characteristics of Ice-Covered Insulators

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