Protective relay maintenance and application guide. Final report
- Edan Engineering Corp., Vancouver, WA (United States)
Protective relaying is an integral part of any electrical power system. The fundamental objective of system protection is to quickly isolate a problem so that unaffected portions of the system can continue to function. Under normal conditions, protective relays remain idle and serve no active function. However, when required to operate because of a faulted or undesirable condition, it is imperative that the relays function correctly. Failure of a protective relay to contain and isolate an electrical problem can have severe plant-wide repercussions. When an expected protective function does not occur, the end result of an electrical abnormality may be catastrophic equipment damage and prolonged downtime instead of localized minor damage. Another point of concern is undesired operation of a protective relay during normal plant conditions or tolerable transients. Inadvertent relay operation can result in unnecessary system or plant downtime. A strong maintenance and test program will help ensure protective relays respond properly to normal and abnormal conditions. NMAC has created this guide to provide practical and cost-effective guidance for implementing a successful protective relay maintenance program and to eliminate ambiguity over which inspections and tests to conduct under different circumstances. It is difficult to find clear guidance on which inspections and tests to conduct within defined maintenance categories for protective relays. This guide contains technical information applicable to electromechanical protective relays in use at power generating stations. A description of protective relay operating principles, construction, applications, degradation mechanisms, and failure modes is provided in addition to maintenance recommendations. A key topic addressed in this guide is optimization of test intervals. One possible method for evaluating relay performance data in support of optimizing maintenance intervals is presented.
- Research Organization:
- Electric Power Research Inst., Palo Alto, CA (United States); Edan Engineering Corp., Vancouver, WA (United States)
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 10126058
- Report Number(s):
- EPRI-NP-7216; ON: UN94007152; TRN: 94:002901
- Resource Relation:
- Other Information: PBD: Dec 1993
- Country of Publication:
- United States
- Language:
- English
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