Chandrapur back-to-back HVDC converter station

The Chandrapur back-to-back HVDC station connects India's western and southern power grids near the city of Chandrapur. Owned by Power Grid Corporation of India, its primary function was to export power from the Chandrapur Super Thermal Power Station to the southern grid. The station consists of two independent poles, each rated at 500 MW, built by GEC-Alstom between 1993 and 1997 with nominal DC voltage and current ratings of 205 kV and 2475 A. The station is located 20 kilometres from the eastern terminal of the Chandrapur–Padghe HVDC system. Due to its proximity to another converter station (built by a different manufacturer), control systems required careful coordination, achieved through joint simulation studies involving both stations' equipment. On 31 December 2013, the Northern, Eastern, and Western grids were synchronized with the Southern grid, creating a single synchronous AC grid across India. As a result, the station is no longer needed for its original purpose of asynchronously linking the Western and Southern grids but can still function as an embedded power flow device to manage power distribution within the AC system. The station's design includes two poles, each with 12-pulse bridge converters without DC smoothing reactors. Each pole has three single-phase, three-winding converter transformers on both sides, along with 48 thyristor valves (12 per end of each pole), each containing 54 thyristor levels rated at 5.2 kV. The station also features 848 MVAr of AC harmonic filters and two 50 MVAr shunt reactors on the Southern side. Despite its seismic location, the ...