Hioki 3169-20 - Page 191

13.1 Formulae
183
13
2
3
4
5
6
7
8
9
10
11
*1: The calculation is performed internally, and the result is not
displayed on-screen, when the reactive-power-meter method is
used. The calculation is not performed when the reactive-
power-meter method is not used.
*2: The calculation is performed internally, and the result is not
displayed on-screen.
*3: The phase voltage from a virtual neutral point is used for
calculation of
P
,
Q
.
P
k
=
u
1kr
I
1kr
+
u
1ki
I
1ki
+
u
2kr
I
2kr
+
u
2ki
I
2ki
+
u
3kr
I
3kr
+
u
3ki
I
3ki
Q
k
= (
u
1kr
I
1ki
-
u
1ki
I
1kr
)+ (
u
2kr
I
2ki
-
u
2ki
I
2kr
) + (
u
3kr
I
3ki
-
u
3ki
I
3kr
)
*4:
U
1s
=
u
1s
-
u
2s
,
U
2s
=
u
2s
-
u
3s
,
U
3s
=
u
3s
-
u
1s
U
: Line to line voltage; u: Phase to neutral voltage from a virtual
neutral point
*5:
I
3s
= -
I
1s
-
I
2s
(provided that
I
1s
+
I
2s
+
I
3s
= 0 )
*6:
U
3s
=
U
1s
-
U
2s
(provided that
U
1s
+
U
2s
+
U
3s
= 0)
*7: When
P
k
=
Q
k
= 0,
φ
k
= 0°.
*8: When
S
k
= 0,
φ
k
= 0°.
Apparent
power
S
k
[VA]
*2
S
1k
S
1k
+
S
2k
The reactive-power-meter
method is used.
S
1k
+
S
2k
+
S
3k
The reactive-power-meter
method is not used.
Power
phase
angles
φ
k
[deg]
The reactive-power-meter
method is used.
tan
-1
*7
The reactive-power-meter
method is not used.
cos
-1
*8
Wiring
Item
Single-phase 2-wire Single-phase
3-wire
Three-phase 3-wire Three-phase
4-wire
1P2W 1P3W 3P3W2M 3P3W3M 3P4W,3P4W4I
P
k
2
Q
k
2
+
3
3
--------
S
1k
S
2k
S
3k
++()
Q
k
P
k
--------



P
k
S
k
-------



• The subscript numbers represent measurement-channel num-
bers. (
k
: Analysis order)
• The expressions above represent the kth harmonic. In the
expressions for total values,
k
is replaced by K.