Hioki 3197, Instruction Manual

Page: 166 / 200

8.5 Calculation Formulas
158
Wiring
Configuration
Parameter
Single-
Phase
2-Wire
*1
Single-Phase
3-Wire
Three-phase, 3-wire Three-Phase 4-Wire
1P2W 1P3W 3P3W2M 3P3W3M 3P4W 3P4W2.5E
Active Power
*2
P [W]
P
1
Psum = P
1
+P
2
Psum = P
1
+P
2
+P
3
(Using Ucs as phase voltage)
Apparent
Power
S [VA]
S
1
Ssum = S
1
+S
2
(Using Uc as inter-line voltage )
Ssum = S
1
+S
2
+S
3
(Using Uc as phase
voltage)
Sc = U
c
x
I
c
Reactive
Power
Q [var]
Q
1
Power Factor
PF
PF
1
Displacement
Power Factor
DPF
DPF
1
•
Subscript definitions
c: Measurement Channel (1 to 3 ), 1, 2, 3: Measurement Channel, M: Sample count, s: Sample point
number,
ave
: average of multiple channels; sum: sum of multiple channels
• Variable definitions
U: Inter-line voltage (three-phase 4-wire phase voltage), I: line current, u: phase voltage from virtual
neutral
si : Polarity sign of lead and lag (using sign of fundamental waveform reactive power)
The polarity sign of the leading phase (LEAD) is “–” when the polarity of fundamental waveform
reactive power is positive.
The polarity of the lagging phase (LAG) is unsigned when the polarity of fundamental waveform
reactive power is negative.
*1. Formulas that apply to inputs 1 to 3 for single-phase wiring also apply to c in other wiring
configurations.
*2. The polarity of Active Power P is (+) for consumption and (–) for regeneration, indicating the pow-
er flow direction.
*3. When S<|P| due to a measurement error or unbalance effect, processing is performed with S=|P|,
Q=0 and PF=1
*4. When S=0, processing is performed with PF=1.000
Pc
1
M
-----
Ucs Ics
× ( )
S 0 =
M 1 –

=
Ssum
3
3
------
S
1
S
2
S
3
+ +
( )
=
Qsum si S
sum
2
P
sum
2
– =
Qc si S
c
2
P
c
2
– =
PFsum si P
sum
S
sum
------------
=
PF
c
si
P
c
S
c
-----
=
DPFsum si
P
sum 1
( )
P
su m 1
( )
2
Q
su m 1
( )
2
+
------------------------------------------------------
=