The application of new analogue and digital techniques to the design of a distance protection relay

This paper describes the development of a family of power system distance protection relays. The development embraces advanced analogue and digital techniques, to provide high performance next generation relays designed to function either stand-alone or as part of modern integrated control and protection schemes. Many new features not previously available will be offered, enabling enhanced power system operation. By returning to fundamental distance protection theory, and combining this work with the latest analogue and digital technologies, the new distance protection scheme offers levels of operation and flexibility not previously available. Although a major advance on the previous generation of distance protection, the philosophy behind the relay settings remains largely compatible with older protection relays, so that the existing base of systems application knowledge can be readily transferred.