We all know SAIFI and CAIDI and other IEEE indices, but how many of you have used SARFI?
According to IEEE 1564 it is:
“The System Average RMS Variation Frequency Index (SARFI) Report shows the count of voltage sags and / or swells for the selected sources based on the SARFI indices. Use this report to analyze voltage sag and / or swell incidents, to assess possible impacts on your facility or processes, and to help quantify the performance of power system”
In layman’s terms it measures how large the voltage sag is and counts the number of times it occurs based on the size (e.g., SARFI-10 is a 10% sag, SARFI-70 is a 70% sag)
As more and more distributed resources enter the grid, customer complaints of sags (and swells) are increasing.
In most utilities the sensors to record localized sags do not exist, and so customer complaints are the most common way to monitor voltage issues.
Will the industry have to start proactively monitoring for SARFI and report to regulatory agencies?
Doug Houseman
Expert Member
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