This EPSRC project, funded under the Grand Challenge
Programme, is concerned with determining the suitability of GIL for long
transmission lines. It is proposed to identify critical properties for SF₆
replacement gas and carry out laboratory tests on CF₃I gas and its
mixtures to determine insulation performance and quantify the effects of particulates
in an experimental test cell.

In parallel with the experimental programme, power systems
studies (steady-state and transient) will investigate GIL performance compared
with other transmission options, and determine length, power transfer and other
electrical limits. A test programme on a trial CF₃I GIL will be
established.