Electric field optimization on 150 kV GIS spacer using functionally gradient material

This paper deals with the electric field optimization on the spacer of 150 kV Gas Insulated Substation (GIS) using Functionally Gradient Material (FGM). The basic spacer model is made from epoxy resin with permittivity equals 3.5. The dimension of basic spacer and spacer with FGM modification is same. FGM is done by composing 90% of spacer with epoxy resin and 10% of spacer with higher permittivity. Titanium Oxide (TiO2) with relative permittivity 8.4 is chosen as grading material. Therefore, the spacer with FGM consists of epoxy resin with relative permittivity 3.5 and Titanium Oxide (TiO2) with relative permittivity 8.4. The Titanium Oxide material is placed on the top and the bottom of the epoxy resin material. The maximum electric field intensity on 150 kV GIS spacer without modification is 138 kV/cm [17]. The maximum electric field intensity is still below the electric field breakdown of epoxy resin (197 kV/cm) [18]. FGM modification with Titanium Oxide (TiO2) layer reduces the maximum electric field on spacer to 56 kV/cm.