Chandrapur back-to-back HVDC converter station

The Chandrapur back-to-back HVDC station is a back-to-back HVDC connection between the western and southern regions in India, located close to the city of Chandrapur. Its main purpose is to export power from the Chandrapur Super Thermal Power Station to the southern region of the Indian national power grid. It is owned by Power Grid Corporation of India.

The converter station consists of two independent poles, each with a nominal power transmission rating of 500 MW. Both poles were built by GEC-Alstom between 1993 and 1997 and have nominal DC voltage and current ratings of 205 kV, 2475 A.

The converter station is located 20 kilometres (12 mi) from the eastern terminal of the Chandrapur–Padghe HVDC transmission system. The close proximity of the two converter stations meant that the control systems needed to be carefully coordinated, a task made more challenging by the fact that the two stations were built by different manufacturers. To address this problem a series of joint simulation studies, involving the control equipment from both converter stations connected to a common simulator, was performed.

On 31 December 2013, the Northern, Eastern and Western grids were synchronised with the Southern regional grid, creating a single synchronous AC grid over the whole of India. As a result, the converter station is no longer required for its original purpose of asynchronously linking the Western and Southern grids, although it can still be used as an embedded power flow device to help control power flow within the AC system. The stations could potentially be shifted to elsewhere to export/import power from other countries. Sometimes the excess power fed to the southern grid by this HVDC link is flowing back to Western region through the 765 kV AC lines between Southern grid and the Western grid with futility.