MAIFI

The Momentary Average Interruption Frequency Index (MAIFI) is a reliability indicator used by electric power utilities. MAIFI is the average number of momentary interruptions that a customer would experience during a given period (typically a year). Electric power utilities may define momentary interruptions differently, with some considering a momentary interruption to be an outage of less than 1 minute in duration while others may consider a momentary interruption to be an outage of less than 5 minutes in duration. MAIFI is calculated as

$mbox\{MAIFI\}\; =\; frac\{mbox\{total\; number\; of\; customer\; interruptions\; less\; than\; the\; defined\; time\{mbox\{total\; number\; of\; customers\; served$

MAIFI has tended to be less reported than other reliability indicators, such as SAIDI, SAIFI, and CAIDI. However, MAIFI is useful for tracking momentary power outages, or "blinks," that can be hidden or misrepresented by an overall outage duration index like SAIDI or SAIFI.

Momentary power outages are often caused by transient faults, such as lightning strikes or vegetation contacting a power line, and many utilities use reclosers to automatically restore power quickly after a transient fault has cleared.

ee also

*SAIDI
*SAIFI
*CAIDI
*CAIFI
*Autorecloser