YOKOGAWA CW500, Getting Started Manual, Page: 79 / 87

56
IM CW500-02EN
Harmonic reactive power Qk [var] (used only in internal computation)
Equation
Pc
k
= V
c(10k)r
×A
c(10k)i
- V
c(10k)i
×A
c(10k)r
c: measurement channel, k: harmonic order,
r: real component after taking the FFT,
i: imaginary component after taking the FFT
The measurement interval of the above equation is 10 cycles.
For 12 cycles, replace “(10k)” with “(12k)” in the equation.
1P2W-1 to 4
Q
1k
, Q
2k
, Q
3k
, Q
4k
, Q
sumk
= Q
1k
+Q
2k
+Q
3k
+Q
4k
1P3W-1, 2
Q
1k
, Q
2k
, Q
sum1k
= Q
1k
+Q
2k
Q
3k
,
Q
4k
,
Q
sum2k
=
Q
3k
+Q
4k
Q
sumk
= Q
sum1k
+Q
sum2k
3P3W-1, 2
Q
1k
, Q
2k
, Q
sum1k
= Q
1k
+Q
2k
Q
3k
, Q
4k
, Q
sum2k
= Q
3k
+Q
4k
Q
sumk
=
Q
sum1k
+Q
sum2k
3P3W3A
Phase voltage Q
1k
: V
1
= ( V
12
- V
31
) / 3 , Q
2k
: V
2
= ( V
23
- V
12
) / 3 ,
Q
3k
: V
3
= ( V
31
- V
23
) / 3 , Q
sumk
= Q
1k
+Q
2k
+Q
3k
3P4W
Q
1k
,
Q
2k
,
Q
3k
,
Q
sumk
=
Q
1k
+Q
2k
+Q
3k
Total harmonic voltage distortion THDVF [%]
Display digits 4 digits
Display range 0.0% to 100.0%
Equation
( )
1
100
50
2
2
c
ck
c
V
V
THDVF
k
×
=
∑
=
c: measurement channel
V: harmonic voltage
k: harmonic order
1P2W-1 to 4 THDVF
1
1P3W-1, 2
THDVF
1 ,
THDVF
2
3P3W-1, 2 Line voltage THDVF
12 ,
THDVF
32
3P3W3A Line voltage THDVF
12 ,
THDVF
23 ,
THDVF
31
3P4W THDVF
1 ,
THDVF
2 ,
THDVF
3
Specifications