PROPOSED STATISTICAL PERFORMANCE-MEASURES FOR MICROPROCESSOR-BASED TRANSMISSION-LINE PROTECTIVE RELAYS .1. EXPLANATION OF THE STATISTICS

The paper presents practical calculations and novel techniques for col lecting performance data from protective relays. The methods are focus ed on, but not limited to, microprocessor-based transmission line rela ying systems. Standard definitions are presented for Availability, Dep endability, Security Hardware MTBF, Relaying MTBF, Repair Time, and ot her measures of interest for specific relay types. The paper explains the novel concept of Exposures, the key to a standardized security mea sure. A companion paper, Part II - Collection and Uses of Data, gives practical guidelines for gathering and calculation of results. With th ese standard measures, relay users will be able to compile the first c onsistent industry-wide data base for relay performance assessment.