IEEE 1564:2014 pdf free download

IEEE 1564:2014 pdf free download.IEEE Guide for Voltage Sag Indices.
6.2.1 SARFI-X
SARFI-X corresponds to a count or rate of voltage sags. interruptions, andor swells below or above a specified voltage threshold. For example, SARFI.90 considers voltage sags and interruptions that are below 0.90 per unit, or 9O of the rctircnce voltage. SARFI-70 considers voltage sags and interruptions that are below 0.70 per unit, or 70% of the rcfcrencc voltage. SARFI-l 10 considcrs voltagc swells that arc abovc .1 per unit, or I 10% of the reference voltage. The SARI l-X indices arc meant to assess shon-duration rim variation events only, meaning that the only events included in its computation are those with durations less than the minimum duration of a sustained interruption as defined by IEEE Std I 159. which is I mm.
6.2.2 SARFI-Curve
SARFI-(’urve corresponds to a rate of voltage sags below an equipment compatibility curve. For exampte, SARFI-CBEMA considers voltage sags and interruptions that arc below the lower Computer Husiness Equipment Manufacturers Association (CHEMA) curve (CHEMA is now the lTl).5 SARFI-ITIC considers voltage sags and interruptions that are below the lower lTlC curve. SARFI-SEMI considers voltage sags and interruptions that are below the lower SEMI curve. Again, these curves limit the duration of an rms variation event to the minimum duration of a sustained interruption as defined by IEEE Std 1159. which is I mm.
6.3 Voltage sag tables
A commonly used method of presenting the performance ola site is by means of a voltage sag table. The columns of the tables represent ranges of voltage s’g duration, while the rows represem ranges of retained voltage. F.ach cell in the table gives the number of events with the corresponding range of retained voltage and duration. Each event (that is, each combination of retained voltage and duration) is tabulated in only one cell of the table. Different values arc in use lbr the boundaries bctwcen the cclls. Some possible table choices are presented in 6.3.1.6,3.2. and 6.3.3. In each example, a maximum voltage sag duration of I mm has been used, which is consistent with the minimum duration of a sustained interruption as defined by IEEE Sid 1159. (Note that IEEE Std 1366 uses a minimum of S mm for a sustained intempion instead, since the recommended practice has a reliability conlcxt. The context of’ IEEE Std 1159 Li power quality.l
In the example voltage sag tables below, the retained voltage is expressed in percent, but it may also be expressed in volt.s The duration should be expressed in milliseconds. seconds or minutes, with the exception of the first column, for cases in which the maximum duration is one cycle.
A voltage sag table can be used as a system index as well as a site index. Strictly speaking, a voltage sag table is not an index but a way of presenting a set of indices. Each element in the table can be used as an index, just as there arc multiple choices for the SARFI indices.
A distinction between short.duration intemipsions and other voltage sags is made already when defining the range of retained voltages. In cases in which short.duration interruptions are treated dillerently from other voltage sags, the lower row of the table should start at 10/. or 10%.