Chennai: Driven by need and denied help, India developed its own super computers, learnt to put satellites in space and mastered the pressurised heavy water reactor nuclear technology. While these do not make India a scientific super power, they do fetch the country a measure of respectability.
Now, the same need is driving India to the cutting edge of technologies in another field — power transmission.
The 400-km distance between Wardha and Aurangabad may not be very long, but the cables which connect the two cities in Maharashtra will, in a couple of years, have the distinction of being the world’s highest capacity power transmission line. At present, it is “charged to 400 kV” but when the Power Grid Corporation of India is ready, the capacity of the line will be raised to 1,200 kV. Nowhere in the world does a 1,200-kV line exist, partly because other countries do not need such high capacity lines. China, another country of distances, which does need ultra high voltage transmission, has a 1,100 kV line in commercial operation.
The Wardha-Aurangabad transmission system takes off from a 2 km-long pilot line that the public sector PGCIL has been experimenting in Bina, Madhya Pradesh. The pilot was to study how electrical systems behave when a current of 1,200 volt zips through them.
The ultra high voltage (UHV) systems have one significant advantage — they can carry more power. This is crucial in a country where laying new lines is a challenge because of ‘right of way’ problems.
“UHV is an evolving technology, specially initiated by countries with large surface areas like China and India,” says John Yesuraj, Deputy General Manager, Design and Technology, Crompton Greaves Ltd. “India’s ambition of 1,200 kV system, which would be a step greater than China’s 1,100 kV, is now widely discussed in international technical forums across the world,” Yesuraj told Business Line.
Cromption Greaves recently announced the setting up of a Rs 40-crore ‘UHV lab’ to test how well the various transmission equipment can withstand electrical stress when current of very high voltage, up to 1,600 kV, passes through it. The lab will enable local manufacture of UHV products, substituting costly imports.
In the meantime, Power Grid Corporation is all set to begin research into superconducting transmission systems. Superconductivity has been in physics books for long, but is yet to come into reality. Basically, if you pass electricity through a wire, the wire resists the flow and this resistance heats up the wire and some energy is lost as this heat. A superconducting system keeps the cable under extremely low temperatures, so low that making it possible at temperatures of -135 degrees Celsius is called ‘high temperature super conductivity’. The challenge is, of course, to keep the cable so cold but if you get it right, there will be practically no transmission losses.
Power Grid Corporation will soon be set up a research centre in collaboration with IIT Kharakhpur, the company’s Director-Operations, I. S. Jha, said
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