Design of +/- 1100 kV UHVDC transmission line

There has been a remarkable growth of Indian Power System in the recent years and POWERGRID has played an important role in sustainable development of transmission system in the country commensurating with generation additions. One of the main features of the development by POWERGRID has been the introduction of new & latest technologies and higher voltage transmission systems in the country on a continuous basis. With the ambitious power development program in the country, higher capacity lines have become essential with establishment of high capacity power stations and power pools. Bulk power transmission not only facilitates reduction in number of new lines to be constructed but also offers relief for ever increasing right of way constraints. Besides construction of a large number of 765 kV single circuit and double circuit transmission lines, implementation of +/- 800 kV UHVDC lines has been undertaken by POWERGRID for bulk transmission of power through long distance. A 1200 kV test station including 1200 kV test line has been established recently by POWERGRID with collaboration of various domestic manufacturers in the country and construction of an upgradable 1200 kV line is under progress.

As a further development in the field of HVDC transmission, studies for design & optimization of +/- 1100 kV UHVDC line have been undertaken considering its requirement in future for facilitating bulk power transfer of the order of 10000 MW or more & over distances in range of 2000–2500 km. The paper briefly highlights development of HVDC transmission system in India and the studies undertaken by POWERGRID for evolving designs for +/- 1100 kV UHVDC transmission line. Salient observations and results of the preliminary design & optimization studies have been presented in the paper.