Experiences in manufacturing, testing, installing and operating of 500kV cable systems including Temperature Sensing and PD monitoring

摘要

Throughout the world an increasing amount of cross-linked polyethylene (XLPE) cables is being used. In recent years remarkable achievements have been made to manufacture reliable, long-lasting cables and accessories for extra high voltage (EHV). Thanks to ongoing investments in research and development, new products have been continuously introduced into the market. One of the latest developments in cable technology concerned 500 kV XLPE cable systems, where the first projects featuring this voltage level are already successfully in operation. Based on a specific cable system project, this paper addresses the following aspects: Design of the cables. Manufacturing of the cables. Routine testing of the cables. Installation of cable system on site. Distributed Temperature Sensing (DTS). Partial Discharge Monitoring (PDM). Operation of the cable system. Apart of a description of the encountered experiences in each of the above-mentioned steps, the paper focuses on the added value generated by the advanced diagnostic monitoring systems of the cable system. Due to intensified competition in a liberalised market, the requirement to delete unnecessary safety margins will further push the implementation of advanced monitoring systems. In addition, a general trend of monitoring critical high voltage devices is seen in the power engineering business. Therefore, to allow a safe cable operation without oversizing the cable itself, a clearly increased request for DTS systems has been noted over the last years. Likewise, systems to measure and survey partial discharges (PD) in high voltage cables and their accessories are increasingly requested within the last years to ensure that especially the cable accessories are in healthy condition. Especially for cable systems with voltage levels above 220 kV, such systems are applied more and more often.