The Talcher–Kolar HVDC system, otherwise known as the East–South interconnection II is a 1450 km

HVDC A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating curre ...

transmission connection between the eastern and southern regions in India connecting four states namely

Odisha Odisha (English: , ), formerly Orissa ( the official name until 2011), is an Indian state located in Eastern India. It is the 8th largest state by area, and the 11th largest by population. The state has the third largest population of ...

Andhra Pradesh Andhra Pradesh (, abbr. AP) is a state in the south-eastern coastal region of India. It is the seventh-largest state by area covering an area of and tenth-most populous state with 49,386,799 inhabitants. It is bordered by Telangana to the ...

Tamil Nadu Tamil Nadu (; , TN) is a state in southern India. It is the tenth largest Indian state by area and the sixth largest by population. Its capital and largest city is Chennai. Tamil Nadu is the home of the Tamil people, whose Tamil language ...

and

Karnataka Karnataka (; ISO: , , also known as Karunāḍu) is a state in the southwestern region of India. It was formed on 1 November 1956, with the passage of the States Reorganisation Act. Originally known as Mysore State , it was renamed ''Karnat ...

. The system has a transmission voltage of ±500 kV and was originally put into service in March 2003,Nayak R.N., Sasmal R.P., Sen S., Pelly B., Riedel P., Experience with blocking devices during monopolar operation of +/- 500kV, 2000MW Talcher–Kolar HVDC system in India, CIGRÉ session, Paris, 2006, paper reference B4-204. with a rated power of 2000 MW. In 2007 the scheme was upgraded to 2500 MW. The Talcher–Kolar HVDC system is owned by Power Grid Corporation of India and the converter stations were built by Siemens. The scheme is a conventional bipolar system with overhead lines for the high-voltage conductors and ground return for the neutral current. Hvdc bipolar schematic

Ground electrodes

The scheme includes two ground electrodes, of ring construction, located at Rohila, 28.5 km northeast of the Talcher converter station and at Chikkadasarahalli, 30 km northwest of the Kolar converter station. However, the soil conditions at some distance from the electrode at Chikkadasarahalli were later found to have higher than expected soil resistivity. These geological effects gave rise to problems with DC currents flowing into the neutral connections of

transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...

s at nearby AC substations, which required the addition of DC blocking devices.

Sites

References

External links

* https://web.archive.org/web/20121013104458/http://www.powergridindia.com/PGCIL_NEW/home.aspx Power Grid Corporation of India * http://www.energy.siemens.com/hq/en/power-transmission/hvdc/?stc=wwecc120599 Siemens HVDC website 2003 establishments in Orissa HVDC transmission lines Electric power transmission infrastructure in India Converter stations Energy in Odisha Energy infrastructure completed in 2003 {{powerline-stub