
KEW6315 Items measured at Harmonics measurement
KEW6315 - 146 -
Harmonics reactive power Qk [var]
(used for internal calculation only)
Equation Pc
k
=V
c(10k)r
×A
c(10k)i
-V
c(10k)i
×A
c(10k)r
c: Measurement channel: A
1k,
A
2k,
A
3k,
A
4k
, k: Harmonics of each order
r: Real number after FFT conversion, i: Imaginary number after FFT conversion
Measurement cycle in this equation is 10-cycle. For 12-cycle measurement,
"10k" should be replaced with "12k”.
1P2W-1 to 4 Q
Q
Q
Q
Q
=Q
+Q
+Q
+Q
1P3W-1 to 2 Q
Q
Q
=Q
+Q
Q
Q
Q
=Q
+Q
Q
=Q
+Q
3P3W-1 to 2 Q
Q
Q
=Q
+Q
Q
Q
Q
=Q
+Q
Q
=Q
+Q
3P3W3A Phase voltage Q
1k
:V
1
= ( V
12
-V
31
)/3
,
Q
2k
:V
2
= ( V
23
-V
12
)/3
,
Q
:V
= ( V
-V
)/3
Q
=Q
+Q
+Q
3P4W Q
1k,
Q
2k,
Q
3k,
Q
sumk
=Q
1k
+Q
2k
+Q
3k
Harmonics voltage total distortion factor THDVF [%]
Displayed digit 4-digit
Display range 0.0% - 100.0%
Equation
( )
1
100
50
2
2
c
ck
c
V
THDVF
k
×
=
∑
=
c: Meas. channel
V: Harmonics voltage
k: Harmonics of each order
1P2W-1 to 4 THDVF
1
1P3W-1 to 2 THDVF
1 ,
THDVF
2
3P3W-1 to 2 Line voltage THDVF
12 ,
THDVF
32
3P3W3A Line voltage THDVF
12 ,
THDVF
23 ,
THDVF
31
3P4W THDVF
1 ,
THDVF
2 ,
THDVF
3
Harmonics current total distortion factor THDAF [%]
Displayed digit 4-digit
Display range 0.0% - 100.0%
Equation
( )
1
100
50
2
2
c
ck
c
A
THDAF
k
×
=
∑
=
c: Meas. ch THDAF
1 ,
THDAF
2 ,
THDAF
3 ,
THDAF
4
A: Harmonics current
k: Harmonics of each order
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