CO-OPERATIVE RESEARCH INTO THE ENGINEERING AND DESIGN OF A NEW DIGITAL DIRECTIONAL COMPARISON SCHEME

The paper reviews the salient features of a major co-operative research, development and site trial validation programme which was initiated in 1980 with the objective of accomplishing a major advance in power transmission system protection. Details of the project are given, together with the research/development methodology found necessary to transform a new approach to directional comparison protection into a next-generation product to meet stringent operational design objectives. The principles of the new scheme are outlined, together with details of the early computer-aided design studies which formed the basis of first prototype digital measuring equipments. Details are also given of the site-trial tests which were performed on the British 400 kv supergrid systems, together with the results of investigations into the performance in long-distance power transmission applications.