Challenges for Designing the HVDC Cable Installation Methodology for Metropolitan Cities in India

With economic growth and changing lifestyles, urban areas are experiencing significant increases in electricity consumption and many demanding the EHV transmission stations in parts of the city center area. Integrating bulk power into urban infrastructure has become essential. However, on the other hand environmental concerns and limited Right of Way (ROW) availability in congested urban areas make overhead lines for bulk power transmission infeasible. Therefore, the most practical approach for urban transmission is through underground EHV cable installation. Underground cables and their accessories, especially at Extra High Voltage (EHV) levels, are expensive. Therefore, maximizing the capacity of this asset becomes crucial. The objective of this paper is to serve as a comprehensive guide for power engineers, offering valuable insights into constructing underground transmission networks in densely populated cities of developing countries. The focus is on enhancing the Current Carrying Capacity (CCC) of cables through the effective use of Fluidized Thermal Backfill (FTB) materials during installation. This approach aims to reduce the thermal resistivity of the surrounding medium of cables, thereby enabling optimal utilization of the cable circuit current carrying capacity. The paper aims to provide specialized compositions of thermal backfill materials surrounding the cable system to optimize its performance and efficiency.