Assessment of the resistance to tracking of polymers in clean and salt fogs due to flashover arcs and partial discharges degrading conditions on one insulator model

Abstract

International audienceThis paper describes the assessment of the resistance to tracking of various polymers after (i) flashover voltage (FOV) and flashover gradient (FOG); and (ii) partial discharges (PDs) measurements in dry, clean and salt fogs on one insulator model using standardised electrodes; the aim being the development of optimised methods based on flashover and PDs to the conception of new generation of piercing connectors. The investigated materials belong to two distinct classes widely used in the electrical industry: thermoplastics (namely polyphenylene sulfide and high density polyethylene) and thermosetting cycloaliphatic epoxy resins namely one unfilled material (UnCEP) and another unfilled and hydrophobic resin (UnHCEP). FOV measurements are based on the electro-geometrical parameters of each specimen and the resistance to tracking, both may be assessed through the slope of FOV curves against the leakage distance as an indicator of surface damages. Regarding PDs, the suggested technique is devoted to clean and salt fogs and provides quicker and more accurate information about PDs effects on materials deteriorations rather than IEC60109 where the exposition time to discharges is much longer at lower voltage levels by using only liquid contaminants such as sulfuric or nitric acids or ammonium chloride as described in IEC60587 or ASTM D2303

Surface Tracking of MgO/Epoxy Nanocomposites: Effect of Surface Hydrophobicity

“…However, besides the intrinsic properties of nanodielectrics, extrinsic surface properties were also found as important factors in our follow-up studies. Electrical properties are inevitably affected by surface conditions, including surface hydrophobicity [24][25][26][27][28]. In this paper, surface tracking measurements were conducted on nano-MgO/epoxy composite samples.…”

Arc Tracking Control in Insulation Systems for Aeronautic Applications: Challenges, Opportunities, and Research Needs

“…New discharges extend existing tracking paths, thus reducing the region of healthy insulation. The applied voltage will generate other carbonized paths on the healthy insulation surface between the high voltage electrode and ground, thus leading to a flashover or a breakdown [14], with the consequent fire hazard [15]. Therefore, arc tracking can be understood by self-sustained arcing between two or more wires across a carbonized path produced due to degradation of the insulation, which can induce ignition of wiring [16], even in 12 volt automotive wiring systems [17] or explosions [3].…”

Effect of superhydrophobicity on surface damage of silicone rubber under AC voltage

“…3 However, it also creates some new problems because of the organic nature of silicone rubber; these include surface damage induced by arc discharge. [4][5][6][7] Because water droplets are present on composite insulators in a humid environment, leakage current can increase, resulting in arc discharge on the insulators. [8][9][10][11][12] The heat from arc discharge can cause surface deterioration of silicone rubber, such as tracking and erosion.…”

“…[8][9][10][11][12] The heat from arc discharge can cause surface deterioration of silicone rubber, such as tracking and erosion. 4,5,13 After tracking occurs, the strength of the insulation is lost and cannot be recovered. 13 Therefore, many researchers focus on how to deter it.…”