YOKOGAWA wt3000, User Manual, Page: 334 / 384

App-2
IM 760301-01E
WP
WP+
WP–
Measurement Functions
during Normal
Measurement
Watt
hour
[Wh]
N
is the number of samples over the integration time. The time unit is h.
WP
is the sum of positive and negative watt hours.
WP+
is the sum of positive
P
(consumed watt hours).
WP–
is the sum of negative
P
(watt hours returned to the power supply).
Integration
Σ
function
q
q+
q–
Integration time
[h:m:s]
Time from integration start to integration stop.
(Table 2/3)
Single-phase,
two-wire 1P3W
Three-phase,
three-wire 3P3W
Three-phase, three-wire (three-voltage,
three-current) 3P3W (3V3A)
Three-phase,
four-wire 3P4W
P1 + P2 + P3 P
Σ
[W]
P1 + P2
U
Σ
[V]
I
Σ
[A]
Wiring system
(U1 + U2) / 2
(I1 + I2) / 2
(U1 + U2 + U3) / 3
(I1 + I2 + I3) / 3
S1 + S2
(S1 + S2 + S3)
3
3
(S1 + S2)
2
3
S
Σ
[VA]
S1 + S2 + S3
Q1 + Q2
Q1 + Q2
Q Σ [var]
Q1 + Q2 + Q3
Q1 + Q2 + Q3
Pc1 + Pc2 + Pc3 Pc1 + Pc2
Pc
Σ
[W]
Ampere hour
[Ah]
Volt-ampere-hour
WS [VAh]
Var-hour
WQ [varh]
RMS,
MEAN,
RMEAN
DC
TYPE1,
TYPE2
TYPE3
TYPE1
TYPE2
TYPE3
I(n)
is the n
th
measured current value.
N
is the number of data updates.
The time unit is h.
I(n) • Time
n = 1
N
1
N
S(n)
is the n
th
measured apparent power value, and
N
is the number of data updates.
S(n) • Time
n = 1
N
1
N
Q(n)
is the n th measured reactive power value, and
N
is the number of data updates.
i(n) • Time
n = 1
N
1
N
i(n)
is the n
th
sampled data of the current signal.
N
is the number of data samples.
q
is the sum of positive and negative ampere hours.
q+
is the sum of positive
i(n)
(ampere hours).
q-
is the sum of negative
i(n)
(ampere hours).
The time unit is h.
P
Σ
2
+ Q
Σ
2
S Σ
2
- P Σ
2
Method of Determination, Equation
For details on the symbols in the equation, see the Note on page App-3.
u(n)
•
i(n)
•
Time
n = 1
N
1
N
Q(n) • Time
n = 1
N
1
N
(Continues to the next page)
Appendix 1 Symbols and Determination of Measurement Functions