The order has been placed by Indian transmission operator Power Grid Corporation of India (POWERGRID). The order value is about $520m and the grid connection is expected to be operational in the first half of 2020.

The 200km-long HVDC connection is claimed to be the first DC link in India to feature voltage-sourced converter (VSC) technology.

According to Siemens, VSC is the latest in HVDC technology which offers stable and flexible reactive power control independent of active power control and additional features that support alternating current (AC) systems.

For the order, Siemens will supply two parallel converters, each rated at 1GW, featuring VSC technology and Sumitomo Electric will be responsible for XLPE HVDC cable system in the DC circuit.

The Pugalur-Trichur ±320 kilovolt (kV) HVDC system will connect Pugalur in the southern state of Tamil Nadu to Trichur in Kerala State in South-West India.

The Trichur converter station will be connected through an underground XLPE HVDC cable to a transition station that will be built by Siemens.

On the other hand, Sumitomo Electric will supply a 128 km XLPE HVDC cable system that has four cables for a route of 32 km each. From the converter station at Pugalur power will be transmitted via an overhead line to the transition station.

The two companies have also entered into a cooperation agreement to work on HVDC transmission for select projects where the technology from the two companies can be combined.

Siemens Energy Management CEO Ralf Christian said: "We are proud to announce that this project will be the first HVDC link in India featuring VSC technology.

"Latest innovations will help achieving ambitious grid programs, like the ‘24 x 7 Power for all’ initiative of India’s Ministry of Power, to meet the growing power demand."

Sumitomo Electric managing executive officer Masaki Shirayama said: "We are pleased to announce this innovative partnership which accommodates the needs of the growing HVDC transmission system market, and we believe this cooperation between technology leaders, Siemens and Sumitomo Electric, will strengthen both company’s capability to provide state-of-the-art HVDC solutions to the customers worldwide."

Image: Officials of Siemens and Sumitomo Electric signing cooperation agreement. Photo: Courtesy of Siemens AG.