NG TGN(E) 182 PDF

This document establishes a functional framework for Standard Bay Designs at 132, 275 and 400kV. The purpose is to outline the functionality and ground rules to guide the designer towards acceptable solutions, which shall be procured for asset replacement, system development and new build projects. The guidance caters for commonly found bays within the transmission system (feeder, transformer, section, coupler and mesh).

A design should provide a cost effective, safe connection, which is simple to install, commission and manage for its whole service life.

The designer will have the freedom to develop a bay design against a functional bay specification (NGTS 2.26), this design will then form the basis of their standard (and repeatable) solution. National Grid intends to agree a set of standard designs, where possible, which can be installed in reasonable population densities.

The bay boundary and interfaces incorporates all elements facilitating the connection between a circuit item (line, cable and transformer) and the busbars. This includes primary plant, light current functions, civil infrastructure and core interfaces with the substation auxiliary systems. Whilst it is appreciated that not all bays will be uniform, where commonality occurs, the supplier should standardise their choice technology and functionality, achieving design efficiency. The equipment specific detail is already available in National Grid Technical Specifications (NGTS). This document brings together the bay specific issues and where uncertainty arises, indicates National Grid's requirement.

Designers should utilise ‘off the shelf' technology in their standard solution. However, we will consider new technology and innovation, where a more cost-effective solution can be demonstrated.

The bay design approach should also encourage suppliers to develop effective and sustainable techniques for asset replacement activities within the live operational substation environment.

This document and the registered designs will be reviewed approximately every 5 years. During this period the development of novel technologies will be evaluated and accordance taken of ‘off the shelf products' which have been developed within this period. This staged approach will be considered for the foreseeable future.