NGC experience with audit of excitation system performance

Since restructuring of the UK electricity supply industry in 1990, technical specifications favoured by the previous vertically integrated industry structure have been replaced through a progressive move to functional performance based specifications. This is particularly true for power station generator excitation system performance. This paper briefly outlines the areas covered by the UK National Grid Company's (NGC's) functional specification and details NGC's experience in auditing excitation system performance and associated data.