YOKOGAWA WT333E - Function

1-12
IM WT310E-01EN
Moving Average
The specified average count is used to compute linear averages according to the equation below.
D
n =
M
n
−
(m
−
1)
+ • • • M
n
−
2
+M
n
−
1
+M
n
m
D
n
:Displayedvalueofthelinearaverageofmitemsofnumericdatafromthen–(m–1)
th
to the n
th
time
M
n–(m–1)
:Numericdataatthen–(m–1)
th
time
………………………………………………
………………………………………………
M
n–2
:Numericdataatthen–2
th
time
M
n-1
:Numericdataatthen–1
th
time
M
n
: Numeric data at the n
th
time
m:Averagecount(selectfrom8,16,32,and64)
Measurement Functions That Are Averaged
The measurement functions that are directly averaged are indicated below. Other functions that use
these functions in their computation are also affected by averaging. For details about how the values
of measurement functions are determined, see appendix 1 in the Getting Started Guide, IM WT310E-
02EN.
Measurement Functions Used in Normal Measurement
• U,I,P,S,andQ
• λ,Φ,CfU,andCfIarecomputedusingtheaveragedvaluesofUrms,Irms,P,S,andQ.
Measurement Functions Used in Harmonic Measurement (Option)
• U(k),I(k),andP(k)
• λ(k)andΦ(k)arecomputedusingtheaveragedvaluesofP(k)andQ(k).
• Uthd,Ithd,Uhdf(k),Ihdf(k),andPhdf(k)arecomputedusingtheaveragedvaluesofU(k),I(k),
and P(k).
k: The harmonic order
Q(k): reactive power of harmonic order k
Measurement Functions That Are Not Averaged
The following measurement functions are not averaged.
Measurement Functions Used in Normal Measurement
 fU,fI,U+pk,U–pk,I+pk,I–pk,P+pk,P−pk,Time,WP,WP+,WP–,q,q+,andq–
Measurement Functions Used in Harmonic Measurement (Option)
ΦU(k),ΦI(k),andfPLL
1.2 Measurement Conditions