Troll A

This second delivery to Statoil, Troll A 3&4, provides a total of 100 MW to the platform to power two compressor drive systems. It is in operation since in 2015.

In 2002, Hitachi Energy was awarded the world's first power from shore transmissions using HVDC Light^® technology to the same platform - Troll A 1&2, which was successfully completed in 2005. The projects combine HVDC Light^® technology and the Hitachi Energy very high voltage (VHV) cable-wound motor. With the second delivery completed in 2015, it consists of four transmissions in total - two rated at 44 MW each, and two rated at 50 MW each - on the mechanical shaft of the VHV Motor.

The inverter stations on the platform are directly connected to the motors, so no transformers are required.  The rectifiers at the Kollsnes onshore station on the Norwegian mainland connect through standard power transformers to the existing 132 kV network with breakers. From the rectifiers, HVDC Light^® cables connect the rectifier with the inverter placed on the Troll A platform, a distance of around 70 km. (See single line diagram.)

The AC side of the inverters is connected to the VHV Motors via breakers and AC cables. The VHV motors' outgoing shafts are directly coupled to gearboxes that deliver the right number of revolutions. The VHV Motors are governed by the HVDC Light^® MACH control system.

Compared with conventional offshore power transmission systems, HVDC Light^® saves weight and reduces the space the system takes up on the platform.

Hitachi Energy has 100% of all world's HVDC power-from-shore projects in operation. Statoil’s Troll A 1&2, delivered in 2005, BP’s Valhall, delivered in 2011, Troll A 3&4, delivered in 2015 and Equinor's Johan Sverdrup, delivered in 2018. All are located in the North Sea.