25 years of successful HVDC experience in India

2014-09-17 - The anniversary of India’s first HVDC station marks a quarter of a decade of successful collaboration – and a great starting point for future developments of the Indian grid.

India’s first high voltage direct current (HVDC) station, designed, manufactured and commissioned by ABB in 1989, completed 25 years of operation. Set up in the Vindhyachal region, this 500 MW back-to-back HVDC station was conceived by NTPC in the early 1980s to transmit locally generated thermal power to the Delhi cluster in the northern grid. Subsequently, the Indian power landscape was restructured, which transferred the station under the transmission company Powergrid Corporation of India Limited (PGCIL).

In the 1980s, the Indian transmission system operated in separate asynchronous regional sub-grids, which meant power generation and consumption had to be scheduled within each region. The Vindhyachal HVDC back-to-back station dramatically increased the flexibility of the Indian grid by permitting power flow between regions, and consequently optimized generation, to meet load variations.

Today, the remote Vindhyachal region, in the central Indian state of Madhya Pradesh, hosts three super thermal power generating stations within a radius of 40 km: the 2,000 MW capacity Singrauli, the 3,000 MW Rihand, supplying power to the northern grid, and the 4,260 MW Vindhyachal, supplying power to the western grid. The short circuit levels in the region have substantially increased in the last 25 years and Vindhyachal HVDC station has contributed significantly by buffering the impact of this and supporting the power system.

Silver jubilee celebrations

The anniversary was marked by a cultural show by local school students at the station in the Vindhyanagar town, Madhya Pradesh. The event also included a workshop on ‘Life extension of existing systems in India’. Present at the event were Ooman Chandy, Executive Director of HVDC Engineering, PGCIL, R P Sasmal, Director Operations at PGCIL. Sasmal appreciated the level of engagement that ABB has demonstrated over the years saying, “Over the past 25 years, we have been working with ABB. They have been an organization that has shared knowledge and expertise and helped us to master HVDC technology.”

The successful operation of the Vindhyachal station ushered in the ‘HVDC-era’ in India, unifying asynchronous regional grids, to lay the foundation for grid stability and reliable power supply across the country. Today, the country has 10 HVDC links, 16 stations in operation, and three links with seven stations under execution. This includes world’s first multi-terminal UHVDC transmission link, the ±800 kV North-East Agra UHVDC link with 8,000 MW converter capacity to transmit clean hydroelectric power from India's hilly northeast, over a distance of 1,728 km, lighting up 90 million lives in the south.

Six decades of HVDC technology
2014 is also the 60th anniversary of HVDC technology (read more here), in 1954, the world’s first commercial HVDC link was commissioned by ABB. The link, between the Swedish mainland and the Island Gotland, was 100 km long with a capacity of 20 MW at 150 kV. The secret behind the success was the development of mercury arch valves, a project led by Dr. Uno Lamm who started his ABB career in 1928. It took Dr. Lamm and his team 26 years to complete the task and in 1954 they finally succeeded and the Gotland link became a reality.Since then, ABB has continued to deliver many ‘world’s first’ in the field.

A back-to-back station has no transmission line and connects two AC grids at voltages, frequencies or phases.