New London Underground BSP goes live

ABB has successfully delivered a major project to create a new Bulk Supply Point (BSP) for London Underground Ltd (LUL), needed to increase the power on the Circle, District, Hammersmith & City and Metropolitan lines to introduce air-conditioned rolling stock.
With a 120 MW (mega watts) capacity, the new BSP takes electricity from a nearby National Grid 400/132 kV substation and steps it down through transformation (132/22/11 kV) to feed into the LU power supply system. The major challenge for ABB has been in working within the compact site, which is hemmed in on all sides with an operating railway close by, to create a large, modern substation building.

The project started in 2009 with excavation of 11,000 cubic metres of spoil and civil works that included extensive deep piling and construction of a new multi-level reinforced concrete building that includes cable and switchgear basements.

Electrical equipment includes three 22/11 kV 25 MVA coupling transformers, two 132/22 kV 120 MVA grid transformers, a 35 panel 22 kV switchboard featuring ZX2 GIS, a 27 panel 11 kV switchboard featuring UniGear AIS, low voltage switchgear, two 11kV earthing/auxiliary transformers, ventilation system and associated mechanical systems, 110 V batteries and charger.

Control elements include SCADA RTU (remote terminal units) for the 11 kV and 22 kV switchgear plus extensive fibre optic cabling. As part of the project, ABB is also laying around 55 km of 22 and 11 kV XPLE (cross-linked polyethylene) cable associated with the BSP.

A major challenge was overcome in the successful installation of the two grid transformers, each weighing 97 tonnes. Delivering the transformers to the central London site was a highly complex logistical exercise requiring months of planning and stakeholder engagement to identify the best route and arrange the necessary traffic management to enable the two massive loads to reach the site with minimum disruption.

The two BSP grid transformers in place