Application of high-temperature superconductive cable lines as components of DC transmission systems for enhancing the reliability of megalopolis electric power supply

The tendency of megalopolis power system development and load increasing results in the necessity of additional substations and power transmission lines building. Nowadays the problem of megalopolis land occupation for overhead transmission lines building is solved by the XLPE (AC cross-linked polyethylene) cable lines application with subsurface cabling. However, adding new transmission lines to power system can result in fault current values increasing and current overload of some transmission lines. For the purposes of fault current limiting and power system controllability enhancement the high-temperature superconductive (HTS) cable lines as a part of DC-ties can be used. In this paper the HTS cable lines application for enhancing the power supply reliability of Saint-Petersburg (Russia) is represented. The efficiency analysis of HTS cables application is considered. The investigation performed is a part of the pilot project of HTS cable lines application in Russian power system.