FEM simulation of local field enhancement close to lamination interface of permittivity‐graded material

Abstract

For size reduction of gas insulated switchgears (GIS), application of permittivity‐graded material to insulating spacer has been studied. The electric‐field‐enhancement close to the lamination interface of the permittivity‐graded material obtained by laminating epoxy composites with different permittivities was investigated. The FEM simulation revealed that the increase of the layer number of the permittivity‐graded material could reduce the field enhancement close by the lamination interface, even when considering electric field distortion near the individual high‐permittivity particles filled in each layer.

Modeling of the Transient Electric Field in Multilayer Dielectric Composites Under Impulsive HV Energization

“…It is remarked that conventional fieldgrading materials designed with field-adaptive characteristics may also be referred to as FGMs, e.g., [3]- [6], but the focus of this study is on materials with spatially nonuniform properties. Both continuous [7] and layered FGMs [8] have been described in the literature, where the former typically provides a smoother field distribution, but with significant manufacturing complexity and at higher cost when compared to the latter. However, in recent times, progress has been made toward more effective fabrication techniques for FGMs, e.g., centrifugal methods using particulate fillers [9], fuseddeposition modelling (FDM) [10], the flexible mixture casting (FMC) method [11], or injection-based techniques [12], among several others.…”

Analytical model for the transient permittivity of uncured TiO 2 whisker/liquid silicone rubber composites under an AC electric field

“…Meanwhile, graded permittivity materials are effectively used for electric field grading [2,3]. Several research groups have demonstrated that a graded permittivity can be achieved by lamination [4,5], centrifugation [6,7], electrophoretic deposition [8], electric field assembly, magnetophoretic methods [9,10], magnetron sputtering [11,12] and three-dimensional printing [13]. Compared with other techniques, the in situ electric field assembly represents the most versatile method that is applicable to any insulation system [14].…”

Study of electric field stress on the surface contour and at the triple junction in three phase GIS with FGM spacer under the depression defect

“…Later Naoki Hayakawa et al [18] identified that ɛ-FGM with spacial distribution is one of the effective methods for the reduction of the electric field in along the length of the spacer, despite several methods, Flexible Mixture Casting (FMC) the method is chosen for the fabrication of ɛ-FGM spacer. Muneaki K. et al [19] reviewed that FEM analysis is a mathematical tool used in the design of FGM spacer by grading the plain epoxy spacer with different permittivity values for the reduction of the electric field stress in the GIS. Few authors [20,21] have identified that electric field intensity is very high at Triple Junction (TJ) due to high electron emission and the reduction in the field stress has been achieved by inserting metal inserts (MI) at this junction of the enclosure end and the conductor end of the cone type spacer.…”

“…This approach relies on reducing the electrostatic energy function. Under steady state electrostatic fields within a dielectric material of constant dielectric strength , with the Cartesian coordinate system, and by using Laplace equation, the electrical energy "W" stored within the whole volume 'v' of the region considered as given below with Equation (19).…”