Study Of Silicone Rubber Composite Insulators Used In Electrical Transmission Lines

The insulator is a general term.It is categorized by thermal and electrical insulators.The electrical insulators play very important role generally in high voltages transmission lines(HVTL).Its application is to provide mechanical support also prevent leakage of current in HVTL.The insulators are generally two type silicone rubber insulator and ceramic insulator.Ceramic material insulators are well known as best electrical insulator.But it cannot withstand in shock loads because it is brittle in material.To overcome of that solution silicon rubber insulator is more suitable as HTVL.Because it can sustain shock loads and also insulate the leakage of current.The major problem in silicon rubber insulator is that,dust particles,water particles and other elements are easily contaminated on its surface.It may cause of degrade the life of silicon rubber insulator.The aim of this work to propose new structure design for silicon rubber insulators.Which reduces the contaminations of dirt and water particles on its surface.The metrological data of solar radiation have been collected from different regions in Libya.The data was collected the throughout year.Overall data is divided into two periods April to September and October to March.From April to September is summer and October to march has winter in Libya.From this data,the optimum angles of incident solar radiation on surface of analysis the thermal degradation.MATLAB programming code has been used in this work to investigate thermal harmonic distortion(THD)on 6KV to 13KV voltages.MATLab Finite element Method(FEM)programming code was used to investigate the analysis of potential distribution and electric field strength on Straight sheds silicone rubber insulators under contaminated and clean conditions.Two model one is accumulated water drops and other is dirt contaminated have been investigated in this work.The results are compared with clean insulator-dust 17%,clean-water drops 10%,and between water drops-dust was 7%.The new proposed design dimensions are according the standard of International electro-technical commission IEC 60815.In this work also investigated electrical and mechanical properties of silicon rubber material by surface tracking test method and the standard is ASTM D-2132.For calculating the mechanical and electrical properties 25*25 cm and 4 mm thick cleaned sizes of sample have been used.The time duration of test was 1500 hrs with exerted force of 1.0±0.05 N of force and>600V to analysis the degradation of mechanical and electrical properties of material.According to the IEC standard dimensions of the newly design of shed insulator it has been observed that shore hardness 3%,tensile strength 1%,and dielectric constant 0.2%.The results obtained that there is no dangerous change observed after the ageing of 1500 hours when exposed the insulator to tracking surface test.