The consortium of Sumitomo Electric and Siemens Energy (Germany) constructed an ultra-high-voltage direct current (HVDC) transmission system, consisting of DC-XLPE cables and VSC^*1 HVDC converter stations, the first of its kind in India. Commercial operation started in March 2021.

This project aimed to build a 2,000 MW transmission system, consisting of underground cables and aerial power transmission lines for a distance of 214 km between the HVDC converter stations in the southern part of India, in order to eliminate power shortages and stabilize the power transmission system. In ultra-high-voltage direct current transmission, a hybrid line of DC-XLPE cables and aerial transmission lines is highly difficult in terms of engineering due to the high load on the cables. Only two such projects had previously gone into operation around the world, both of which were awarded to Sumitomo Electric in Japan. This time, the Company manufactured and installed DC-XLPE cables using its proprietary DC-XLPE insulation material.^*2

India set the goal of achieving a renewable power generation capacity of 175 GW by 2022. The system serves as an important part of the infrastructure to achieve this goal and contributes to promoting efficient use of renewable energy. Sumitomo Electric and Siemens Energy remain committed to offering high-quality and safe products and technologies by taking full advantage of the experience gained in various countries as well as their mutual strength, and thereby contributing to realizing a society powered by clean energy.

*1 VSC (Voltage Sourced Converter): The construction space is smaller than that of conventional line commutated converters (LCCs). Recently, its use has been expanding mainly in Europe.
*2 Proprietary DC-XLPE insulation material: It was jointly developed with Electric Power Development Co., Ltd. (currently J-POWER Transmission Network Co., Ltd.).