YOKOGAWA CW140, User Manual, Page: 183 / 292

19-3
IM CW140-E
Specifications
19
(4) Equations
Voltage RMS
T
T
1
0
v(t) 2 dt
T
T
1
t=0
v(t) 2
Current RMS
T
T
1
0
i(t) 2 dt
T
T
1
t=0
i(t) 2
Active power
P =
T
T
1
0
v( t ) i ( t ) dt
T
T
1
t=0
v(t) i(t)
=
Reactive power (using reactive power meter method)
v (t), i (t): Input signals
T: One period of input signal
3 φ φφ φ φ voltage unbalanced rate
Va
Vb
100%
Unbalanced rate =
Frequency: 45–440 Hz
Calculation accuracy:
(aluculation from measurement) ±1%
• For 3
φ
3W
Vs = (V
12
+V
23
+V
31
)
2
1
: line-to-line voltages for the 3
φ
3W.
• For 3 φ 4W
In the equations, V
12
, V
23
, V
31
for the 3
φ
3W are substituted with V
1n
,
V
2n
, V
3n
, respectively.
19.1 Specifications