Citation

Yip HT, Weller GC, Allan RN. Reliab. Eng. 1984; 9(4): 191-219.

Copyright

(Copyright © 1984, Elsevier Publishing)

DOI

10.1016/0143-8174(84)90050-7

PMID

unavailable

Abstract

Electrical power is transmitted and distributed by a complex and integrated network which is exposed to various types of faults. These faults are usually short-circuits which occur between phases and between phases and earth. To protect the system against these faults, protection systems, based on automatic relay devices, are incorporated into the power system. This paper discusses the principles of these relay systems and describes techniques that have been developed in order to evaluate the reliability of the devices. The paper also discusses the principles of monitoring and self-checking within the relay to reduce the probability of an undetected dormant failure. All the concepts and techniques are illustrated by the analysis of a typical distance protection relay.