Experience on HVDC disconnectors: sizing and performance of the dielectric in conditions of pollution and ice

Abstract

This study presents the results of an investigation on the dielectric sizing and performance of high voltage direct current (HVDC) disconnectors under normal, pollution and ice service conditions. The disconnectors were tested under laboratory conditions to evaluate their ability to withstand voltage stress and to maintain their insulation properties. The disconnectors were also tested under conditions that simulated typical environmental conditions, such as rain, fog, and ice. The results of the study show that the dielectric performance of the HVDC disconnectors is affected by pollution and ice conditions, which can cause flashovers and damage to the insulation. The study also found that the size of the disconnector plays a critical role in its performance, with larger disconnectors performing better than smaller ones. The study suggests that proper sizing of HVDC disconnectors is essential for ensuring their reliable performance under pollution and ice conditions in line with the new technical specification in release at IEC Level like IEC 62271-5[1] and IEC 62271-314[2]. The paper will deal only with air insulated disconnectors, with special attention to the EHV-UHV range (250–1000 kV range) Overall, the results of this study provide valuable insights into the design and operation of HVDC disconnectors in high-pollution and ice environments. The findings can be used to improve the performance and reliability of HVDC transmission systems, which are becoming increasingly important in modern power systems. Further research is needed to fully understand the complex interactions between the dielectric performance of HVDC disconnectors in particular the post polymeric insulators application and the environmental factors