Dr. Redfern started his career with the Electrical Research Division, British Railways Board, Derby as a Scientific Officer in their Electrical Machines Section. Following his PhD studies at the University of Cambridge he joined GEC Measurements, Stafford as Senior Engineer. He then became Head of Applied Research and Long Term Development, then took charge of Static and Distance Relay Test Depts, and later became Overseas Sales Manager. He then joined the University of Bath in 1986. He has been active researcher in electrical power systems for a long while and has developed his interests in the control and protection of distribution system, the connection of embedded generation, integration of renewable energy systems into utility networks, high speed transient based protection schemes, communications for power system control and protection, non-invasive techniques for the location of buried utilities. He has written over 200 learned publications, most of which have been presented to international audiences.

The first distance relays were introduced in 1904 and provided a solution to difficulties with grading over-current relays on interconnected feeders. Later they were developed to provide high speed relaying ideally suited to protecting transmission lines. This tutorial will introduce the basics of distance protection, develop the ideas of using comparators to determine the presence of a fault, introduce the various comparator techniques and describe the various communications assisted protection schemes. Albeit wide ranging, it aims to whet appetites for further study into the subject.

Intended Audience

Engineers and graduate students designing power system protection system.