A National Grid outdoor substation serving Manchester will soon be replaced by a new indoor substation using ABB’s state-of-the-art gas insulated switchgear (GIS).
ABB’s civil engineering team has started work on a £44 million turn-key contract for the complete replacement of Stalybridge 275kV substation - one of the main National Grid substations serving Manchester city centre. The old air-insulated switchgear (AIS) is to be replaced by a new indoor substation based on ABB’s compact, stateof- the-art, gas insulated switchgear (GIS). The project is the first major ABB activity to be carried out as a Joint Activity Solution (JAS) between National Grid and ABB. Under this new collaborative way of working, a core National Grid/ABB team was established at the early project stages to carry out a detailed analysis of the available substation replacement options and to define the optimum solution.
The Stalybridge 11-bay outdoor 275kV substation was originally constructed between 1957 and 1961. It is now in need of substantial refurbishment as the existing circuit breakers are almost life-expired, while the concrete infrastructure is also reaching the end of its useful life. Since the circuits served by the substation are of vital importance to Manchester’s city centre, they are difficult to take out of service. So the new substation has to be constructed off-line.
INDOOR GIS SOLUTION
The JAS team selected the compact indoor GIS solution, rather than AIS, because there is insufficient space on site to accommodate an off-line AIS substation. Furthermore, an in-situ replacement would require piling works to take place adjacent to live equipment and structures that are already known to be in poor condition. The off-line GIS solution has the added benefits of reducing National Grid’s resource requirement and facilitating a more flexible outage programme.
In addition to the complete replacement of the 275kV AIS substation, the project also includes rationalisation of overhead line entries to the substation and system reinforcements, and extension of the adjacent 400kV AIS substation.
NICAP
Stalybridge is the first new-build substation in which ABB is implementing bay solutions for the substation protection and automation systems based on National Grid's standardised NICAP (National scheme for Integrated Control and Protection) philosophy. This approach, using pre-engineered, pre-tested and pre-approved equipment enables the same functionality to be condensed into a much smaller footprint, reduces the amount of on-site work and achieves major reductions in the delivery time for this element.
The 275kV substation replacement is programmed to be commissioned and fully operational by November 2008 with all remaining ancillary work to be completed by February 2009.
Two London contracts
ABB has also won two contracts from National Grid in the London area. The two London contracts cover the extension of two recently-completed high-voltage gas insulated switchgear (GIS) substations serving the capital. The projects, which will run through to 2008, cover the supply of an additional 240MVA 400/132kV supergrid transformer and five GIS switch bays at one site and a new 400/66kV supergrid transformer at another; in both locations ABB is providing additional cabling and equipment.