• Electrical India
  • Oct 5, 2016

Installing Offshore Grid Connection

The offshore substation topside sets sail for Dudgeon offshore wind farm – installation completed…


Siemens is supporting a sustainable future as over 410,000 British homes will be powered by renewable energy when the Dudgeon offshore wind farm is fully developed in 2017. The crucial grid connection, which enables the energy generated by the wind turbines to be transported to shore, has reached another milestone as the topside to the substation sails from Sembmarine SLP in Lowestoft to be installed on site 32 kilometres (km) north of Cromer off the coast of Norfolk.

OFFSHORE SUBSTATION

The offshore substation jacket preparing to sail

  The offshore 1,500 ton steel substation jacket was designed and fabricated at Sembmarine SLP in Lowestoft and is fitted with suction bucket technology – a first for any UK substation project.

JACKET

Jacket already installed in June

  The completed structure took two days to install in the seabed safely and on schedule in early June 2016, and achieved a hard to come by 0.01 degrees vertical position in the water. The structure is serving its purpose in the north sea as a support mechanism for the topside.

INNER LIFE PLATFORM

Inner life of the platform

  The design and construction of the Dudgeon topside was also completed by Sembmarine SLP including the installation of internal services on behalf of STDL, which commenced in August 2015 and all primary equipment was delivered and installed within a six week period from October 2015. The plant comprises two 200MVA 132/33kV power transformers, two 132kV GIS (8DN8) and two boards of nine 33kV GIS (8DA10), as well as numerous secondary equipment including LVAC, LVDC, UPS, control & protection and a back-up diesel generator. The picture shows the topside HVAC room.

UNDER DECK CABLES

Complex installation of the under deck cables

  132kV and 33kV cables and 33kV DURESCA busbar system installed underneath the cable deck (pictured). Installation of the 33kV array circuits down to 'through joints' on the cable deck significantly minimise the installation time and costs offshore. Throughout the topside there is 50,000m of cable.

CONSTRUCTION TOPSIDE

Construction of the topside completed

  Pictured is the integrated 'end product' just days before the 1,700 ton platform with four decks including emergency overnight accommodation for twelve people was loaded onto the barge in preparation to sail.

LOWESTOFT

Topside sets sail and departs Lowestoft harbour

  A momentous milestone is reached as the topside sails in early August, just 18 months following the start of construction.

COAST OF NORFOLK

Reaching its final destination: 32km north of Cromer off the coast of Norfolk

  The actual installation involved pulling the platform into the designated position and connecting it up to the previously anchored base frame. This is the most critical part of installation and cannot be done in bad weather.

INSTALLATION 

Installation completed

  The platform is designed for decades of operation in the rugged North Sea and will be monitored and controlled from land – when it has been commissioned. With the Dudgeon platform, Siemens has completed the 14th installation of an offshore substation.

SIEMENS

Installation completed

  The platform is designed for decades of operation in the rugged North Sea and will be monitored and controlled from land – when it has been commissioned. With the Dudgeon platform, Siemens has completed the 14th installation of an offshore substation.


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