Universal Pilot Wire Differential Protection for Distribution Systems

This paper presents a novel pilot wire differential protection scheme for distribution systems. The concept and principle of conventional pilot wire differential protection is introduced first. Then, several kinds of numerical differential protection schemes using pilot wires as communication channels are discussed in the paper. A novel numerical protection scheme is further described, in which conventional analogue communication and numerical technology are blended for a specially-designed pilot wire differential relay. Studies show that the scheme is able to offer a number of significant advantages for distribution systems.