Flashover Performance of HVDC Iced Insulator Strings

Fan, Jian-Bin; Li, Wufeng; Su, Ziyi; Zhou, Jun

doi:10.1109/tdei.2007.4401215

Cited by 37 publications

(17 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In China, utilities such as China Electric Power Research Institute and Chongqing University have carried out numerous studies on the flashover performance of short-string ice-covered insulators since the 1980s. The experimental results indicated that the characteristic exponent expressing the effects of atmospheric pressure on icing flashover voltage falls in the range of 0.40 to 0.64, and the characteristic exponent expressing the effects of ice accumulation is in the range of 0.088 to 0.143 [4,5,[9][10][11][21][22][23][24][25][26][27][28][29][30][31][32][33]. Thus, the design of an external insulation for ultra-high DC transmission lines under combined conditions of high altitude, contamination, and icing remains a technical puzzle.…”

Section: Introductionmentioning

confidence: 99%

DC Flashover Performance of Various Types of Ice-Covered Insulator Strings under Low Air Pressure

Sun

Jiang

et al. 2012

Energies

View full text Add to dashboard Cite

Abstract:In this study, icing flashover performance tests of typical DC porcelain, glass, and composite insulators are systematically carried out in a multifunction artificial climate chamber. The DC icing flashover voltages of seven typical insulators under various conditions of icing thickness, pollution severity before icing, string length, and atmospheric pressure are obtained. The relationships between icing thickness, salt deposit density as well as atmospheric pressure and the 50% icing flashover voltage are analyzed, and the formulas are obtained by regression method. In addition, the DC icing flashover voltage correction method of typical porcelain, glass, and composite insulator in the coexisting condition of high altitude, contamination, and icing is proposed.

show abstract

Section: Introductionmentioning

confidence: 99%

DC Flashover Performance of Various Types of Ice-Covered Insulator Strings under Low Air Pressure

Sun

Jiang

et al. 2012

Energies

View full text Add to dashboard Cite

show abstract

“…Recently, Li et al [68] established a modest degree of nonlinearity for dc flashover of iced insulator strings, with E 50 = 125 kV/m for 1.6-m strings declining to 90 kV/m for 5.5-m strings under the same icing conditions. The Obenaus model of an arc in series with a distributed resistive layer has been successful for basic modeling of the icing flashover process [67].…”

Section: E Prediction Of Insulator Flashover Voltagementioning

confidence: 99%

Insulator icing flashover

Farzaneh

2013

2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena

View full text Add to dashboard Cite

the insulator is a kind of important electric components, because it plays a role in electrical insulation and plays a supporting role in mechanical, power system and even the development of the whole society to a higher degree of dependence on the performance of insulators, the requirements are also rising. However, in recent years, China's domestic air pollution is serious, the weather conditions are complex, the icing flashover phenomenon has become a serious performance of insulator safety accidents. However, the proposed super hydrophobic materials in this paper, not only the anti icing flashover performance is better than the commonly used coating, and preparation process is sample, high performance, and low cost, which is expected to become a substitute for insulator coating now. the super hydrophobic coating is considered to be one of the important methods to solve the problem of flashover electrical equipment, so the study of high hydrophobicity flashover, super hydrophobic coating with high performance, simple process, low cost plays an important role in electrical equipment and power industry. In this paper, we will use a kind of method which is more powerful, graphene was prepared by electrochemical stripping and poly-two methyl siloxane in a certain proportion to prepare superhydrophobic surface. In this paper, the preparation of superhydrophobic surface, not only has excellent self-cleaning performance, but also has a very low corrosion current density. It is surprising that the superhydrophobic surface prepared by this method has good mechanical stability, and its surface can maintain the super hydrophobicity after the strong impact of the outside world. The method mentioned in this paper is not only capable of preparing a set of super hydrophobic surface self cleaning,mechanical stability is stable as a whole, it also provides a new idea for anti icing flashover of electrical equipment. 1. Introduction With the development of the electric power industry and the gradual improvement of the voltage level, the electrical equipment is playing a more and more important role in people's daily production and life. Of which the insulator is an important part of power system, however, the phenomenon of icing flashover has a great influence on the mechanical and electrical properties of insulators, which will threaten the stability and security of power system operation, resulting in huge economic losses. Take snow disaster in South China in 2008 as an example, the ice coating accidents spread to 13 provinces, State Grid economic losses in the accident up to 10 billion 450 million Yuan, and in daily life, line trip, outage accidents also occur caused by icing [1] , it causes a great impact on people's life. Therefore, it has become one of the most urgent problems to solve the problem of icing flashover. However, there are still a lot of defects in the deicing and anti icing methods currently used, and the efficiency is low and the energy consumption is large. Super hydrophobic coating is a kind of water ela...

show abstract

“…® The influence of insulator length on flashover voltage [68]; and ® The effect of pollution severity [69].…”

Section: Discharge Propagation On Am Ice Surfacementioning

confidence: 99%

Mechanisms of arc propagation over an ice surface /

Farokhi¹

2010

View full text Add to dashboard Cite

Outdoor insulation design with regard to pollution and icing performance is a critical factor for reliability of overhead transmission lines. The majority of failures occurring on transmission lines are caused by environmental conditions such as lightning, pollution and/or ice. Accumulated ice on insulators may initiate corona discharge; these partial arcs sometimes lead to flashover. This phenomenon is mainly caused by the presence of a highly conductive water film on the surface of the ice and ice-free zones, often called air gaps, along the insulators, and decreased insulator leakage distance caused by ice bridging.The general objective of this research is to investigate the physical mechanisms involved in the propagation of electric arc on the surface of ice. In the present research work, high-speed photography techniques was combined with synchronized electrical measurements to study the various parameters of arc on an ice surface, such as channel radius and propagation velocities. These results, together with studying the propagation patterns and arc foot geometries, provide background information for understanding the complete flashover phenomenon. Arc root structure, current profile, propagation pattern and velocity were investigated under positive and negative polarities. Water film conductivity and thickness, and relative air humidity were also analyzed as influencing parameters of arc propagation. The effects of different mechanisms, e.g. collision and thermal ionization, buoyancy force and electrostatic force, on different stages of arc propagation are also discussed.Repetitive patterns corresponding to arc decays were observed during arc propagation. During arc re-ignitions, an anode-directed streamer was found to be dominant, regardless of the polarity of applied voltage. The arc root under de-positive applied voltage was branched; on the contrary, the negative arc root appeared as a diffused luminous region. In the arc channel section, two distinct regions were distinguished. A linear relationship between the initiation current and the inverse of residual resistance was established, showing how important is the effect of water film thickness on the initiation of discharge. It was found there is a direct relationship between the slope of current increase and the applied water conductivity. Air humidity increases the voltage gradient along the arc channel and reduces the discharge activities at the arc tip. However, it could influence the arc formation and its propagation by changing the thickness of the water film. A change in the dominant mechanism from thermal ionization to collision ionization in the enhanced electric field was found to be responsible for the flashover. Tare. L'effet de différents mécanismes comme les collisions et l'ionisation thermique, la force de flottabilité et la force électrostatique sur les différentes étapes de la propagation de l'arc ont également été discutés. 11 RESUME

show abstract

Flashover Performance of HVDC Iced Insulator Strings

Cited by 37 publications

References 4 publications

DC Flashover Performance of Various Types of Ice-Covered Insulator Strings under Low Air Pressure

DC Flashover Performance of Various Types of Ice-Covered Insulator Strings under Low Air Pressure

Insulator icing flashover

Mechanisms of arc propagation over an ice surface /

Contact Info

Product

Resources

About