Comparative performance of 11kV silicone rubber polymeric insulators under Rotating Wheel Dip Test

This paper presents an experimental study of silicone rubber polymeric insulators for 11kV systems using a Rotating Wheel Dip Test (RWDT) based on IEC 62730:2012. The primary aim of this study is to compare the aging performance of polymeric insulators under AC voltages. Different insulator designs are investigated. A conventional polymeric insulator design has been adopted and compared with insulators having a textured surface. Textured surfaces have been developed by Cardiff University to increase the creepage distance and improve tracking/erosion performance. The results of long term testing are obtained; during the test cycle, and both voltage and current traces were acquired continuously. A number of parameters were then calculated during the post processing stage. These parameters include peak values, accumulated absorbed energy, power consumption and power factor angle. Using these parameters allows direct comparison between different insulator designs. In particular, the magnitude and shape of leakage current and the accumulated absorbed energy on the insulator surface were examined to characterise each insulator. Furthermore, continuous monitoring of the shed surfaces and the insulator trunk using an IR camera were undertaken to evaluate the temperature distribution along the surface profile. In addition, hydrophobicity tests were performed before and after completion of the test to evaluate the degradation level of the insulator surface and its material.