It refers to the ability of protective relays to selectively detect and isolate faults, ensuring that only the minimum portion of the system is disrupted. For example, unselective protection operation during a medium voltage network fault will cause an outage for an unnecessarily large number of consumers. While this is bad, It's not a. This document supplements PJM Manual 07 which contains the minimum design standards and requirements for the protection systems associated with the bulk power facilities within PJM. Starting from selectivity, speed, sensitivity, discrimination, stability, reliability, and economics.
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