India steps up to 1,200kV
India is set to deploy 1,200kV power transmission lines on commercial basis, making it the highest voltage level in the world. Boosting India’s prospects is the successful implementation of the 1,200kV test station at Bina in Madhya Pradesh. VENUGOPAL PIL
The development of India’s power sector—in both qualitative and quantitative terms—will be the principal determinant of India’s socioeconomic development. Power transmission and distribution have received much lesser attention as compared with power generation. In fact, power shortages have traditionally been addressed by ramping up power generation capacity. It is only over the past few years that attention is being directed to improving the technical and commercial efficiency of power generated by duly addressing critical issues in the power T&D space.
On the power transmission front, one of the means to achieve greater efficiency is the introduction of highvoltage lines. Today, commercial lines exist up to 765kV, and apart from AC (alternating current) technology, there is widespread deployment of DC (direct current) lines. In terms of high voltage direct current (HVDC) lines, India is establishing lines with ultra high voltages of even ±800kV. An outstanding aspect of India’s power transmission endeavours has been the effort to set up ultra high voltage power transmission lines at 1,200kV— the highest voltage level anywhere in the world as yet.
Though India has yet to establish 1,200kV power transmission technology on a commercial scale, a
good beginning has been made by setting up testing facilities. The Bina UHVAC test station in Madhya Pradesh is the result of the concerted effort of Central transmission utility Power Grid Corporation of India, Central Power Research Institute (CPRI) and 35 Indian suppliers. What is encouraging to note is that the UHVAC test station is based largely on indigenous technology.
Seeds of the UHVAC enterprise were
sown in 2007 when a Project Steering Committee was formed under the leadership of PGCIL and with members from Central Electricity Authority (CEA), industry body IEEMA, CPRI, and leading Indian electrical equipment manufacturers. The UHVAC Bina test station represents an interesting manifestation of the public-private partnership (PPP) philosophy. When PGCIL announced the 1,200kV venture, several equipment manufacturers came up in support. For the 35 manufacturers involved in this project of national importance, it was not merely a “contract” awarded by PGCIL, but an opportunity to contribute to a national cause. All the equipments for the station like transformers, circuit breakers, surge arrestors, insulators, etc were built indigenously. The Bina test station was dedicated to the nation on December 26, 2012. The test centre includes two test bays, one 1,200kV single-circuit line and one 1,200kV double-circuit line. The test lines are around 2 km long.
The following is a brief description of select participants in the successful commissioning of the 1,200kV Bina test station.
Bharat Heavy Electricals Ltd: Central PSU engineering company BHEL supplied a 1,200kV transformer of 333MVA rating. This single-phase auto transformer was developed with indigenous technology and manufactured at its Bhopal plant in
Madhya Pradesh. Apart from this, BHEL also supplied other key equipment like 1,200kV insulators.
Vijai Electricals Ltd: This Hyderabad-based company also supplied a 1,200kV auto transformer of 333MVA rating. Like BHEL, this singlephase transformer was developed with indigenous technology and was produced at the Rudram works near Hyderabad.
Crompton Greaves: Avantha Group company Crompton Greaves (CG) dispatched a 1,200kV capacitive voltage transformer for the Bina UHV test station. Rolling out of the Nashik plant in Maharashtra, the mammoth transformer was developed with inhouse technology.
Larsen & Toubro: This private sector engineering giant was also involved in the 1,200kV power transmission regime. In late 2009, Larsen & Toubro established India's largest transmission line research centre at Kancheepuram in Tamil Nadu. The centre is equipped to test transmission towers of up to 95m height required for 1,200kV power transmission lines. This testing station, according to a statement by L&T, enables to design and validate innovative configurations without any limitations on size, shape and magnitude of loading, which is currently not possible in the industry.
Siemens: Siemens developed a 1,200kV circuit breaker for the Bina test station. This apart, Siemens also supplied surge arrestors of 1,200kV rating. A Siemens official told Electrical Monitor that these arresters were designed and tested at Siemens’ Berlin and Cologne facility in Germany.
Alstom India: Formerly known as Areva T&D, Alstom India supplied a 1,200kV capacitive voltage transformer for the Bina test station. This equipment was developed at the Hosur plant in Tamil Nadu. Alstom has also planned to make other 1,200kV gear including digital current transformers.
KEC International: RPG Group company KEC International was involved in the Bina test station as the EPC contractor for the 1,200kV double-circuit line. The line involves handling of towers each weighing more than 400 tonnes and with a height of 130m. In an exclusive interaction with Electrical Monitor, Ramesh Chandak, MD & CEO, KEC International Ltd expressed pride in being associated with this landmark project. (Full interaction presented elsewhere in this story.)
Supreme & Co: Kolkata-based Supreme was an active supplier of critical hardware for the Bina test station. In an earlier interaction with Electrical Monitor, the company said that it had supplied nearly 80 per cent of the hardware used in the UHVAC centre. Some key equipment included
corona control rings, clamps, connectors, etc.
Hivelm Industries: This Chennaibased company that is a unit of Digivision Electronics Ltd designed and developed a 1,200kV isolator for the Bina test station. The isolator was shipped to Bina in August 2012.
As of now, the Bina UHVAC station is under testing. Going by industry players, the results have been satisfactory. Testing is expected to go on for another couple of years after which India can embark on setting up 1,200kV lines at the commercial level. When it comes to 1,200kV lines, India has established its competence in manufacturing equipment and hardware. The next phase—and of course the most critical one—is to study “live line” conditions, which is to investigate the working of 1,200kV lines at full load on a sustained period of time. The impact of full load is also being studied on the equipment and hardware. Depending on the results of this study, suitable modifications may need to be made for future projects.
THE NEED FOR UHVAC
India, due to its intrinsic conditions, makes a very good application area for ultra high voltage power transmission. India’s current installed capacity is around 2.3 lakh mw and by 2027, installed capacity is likely to touch 7 lakh mw, necessitating the transfer of 5 lakh mw worth of power capacity.
Power transmission is very landcentric activity and land—as a subject—has always had a difficult time. Erecting power transmission lines involves obtaining the everelusive right of way. Securing RoW for lines passing through sensitive areas like forests or mines or through private land has been a big deterrent. Once RoW is obtained, it makes technical and commercial sense to harness it to the fullest. The difference in RoW requirement for a 400kV line and a