UHV Transmission in India

Last updated: January 21, 2017

Indian power system is poised to grow at an accelerated pace. The qualitative and quantitative development of the power sector will be the key factor in country's socio-economic growth. Recent studies by US Department of Energy indicate that India will be the second most rapidly growing country, only after China, in terms of electrical demand.

"The peak demand is expected to grow more than 500 GW by 2026." 

North-east region of India has abundant hydro power resources. More than half the power stations are still thermal power plants. Renewable Energy (RE) sector is also progressing at a rapid pace. Indian Energy Scenario predicts a possibility of 889 GW through RE sources by year 2047. Deserts of Thar, Rann of Katchh are suitable for large wind and solar power plants. 

" By 2027 the installed generation capacity is supposed to touch 700 GW."

Power generation centres are typically Eastern and North-eastern regions, whereas the load centres are scattered across the country. Power evacuation in such a quantum over long distances is really a challenge for the Indian power engineers. Transmission of bulk amount of power over long distances can be accomplished most economically using Ultra High Voltage (U.H.V.) transmission lines. An increase in transmission voltage results in reduced electrical losses, increased transmission efficiency, improved voltage regulation and reduced conductor material. 

In addition, getting Right of Way (RoW) for transmission lines passing through forest areas and private land has been a critical issue in our country. Several transmission projects are getting delayed because of objections from handful of land owners.

Thus, to meet the bulk power transfer requirement and for optimal utilization of Right of Way, large capacity transmission corridors, of Ultra High Voltage (UHV) level, interconnecting the generating resources with load-centres are being planned.

"UHV generally means AC voltages of 1000 kV or more and for DC transmission system it is 800 kV or more." 

1200 kV AC transmission system is being envisaged as the next transmission voltage. Further in this direction, a 1200 kV test station near Bina in the state of Madhya Pradesh (India) along with 1200 kV test lines has been set up to study the characteristics of UHV system under actual conditions. It is expected that in a couple of years we will be able to take our commercial power transmission to the 1200 kV level. 

Also UHV DC transmission system is promoted to facilitate transfer of power from major power plants and to increase the capacity of National Grid. Execution of 1728 km long 800 kV bi-polar Biswanath-Agra DC transmission system worth 12,000 crore INR is a step forward in this direction.

Challenges related to UHV transmission:

Certain challenges related to UHV transmission are to be undertaken. For example, sudden loss of a UHV transmission link may result in serious stability issues. Corona loss at such enormous voltage will be quite high. Also the high electromagnetic fields of these UHV lines may seriously impact the health and environment.