YOKOGAWA WT500 User Manual page 325

Measurement Functions
Used in Harmonic
Measurement
Harmonic voltage distortion
factor Uhdf( ) [%]
Harmonic current distortion
factor Ihdf( ) [%]
Harmonic active power
distortion factor Phdf( ) [%]
Total harmonic
voltage distortion
Uthd [%]
Total harmonic current
distortion Ithd [%]
Total harmonic active power
distortion Pthd [%]
Wiring system
UΣ [V]
IΣ [A]
PΣ [W]
SΣ [VA]
(TYPE3) *
QΣ [var]
(TYPE3) *
λΣ
φU1-U2(°)
φU1-U3(°)
φU1-I1(°)
φU1-I2(°)
φU1-I3(°)
max
U
*1 U(Total) = (k)
k = min
*2 For details about the SΣ and QΣ formula type settings, see section 5.4.
IM 760201-01E
Appendix 1 Symbols and Determination of Measurement Functions
The numbers and characters in the parentheses are dc (when k = 0),
or k (when k = 1 to max).
When the denominator of the
distortion factor is the
total value (Total)
U(k)
U(Total)
I(k)
I(Total)
P(k)
P(Total)
max
U(k)
k = 2
U(Total)
max
I(k)
k = 2
I(Total)
max
P(k)
k = 2
P(Total)
Single-phase,
three-wire
1P3W
(U1 + U2) / 2
(I1 + I2) / 2
2
2
Phase difference between U1(1) and the fundamental voltage of element 2, U2(1)
Phase difference between U1(1) and the fundamental voltage of element 3, U3(1)
Phase difference between U1(1) and the fundamental current of element 1, I1(1)
Phase difference between U1(1) and the fundamental current of element 2, I2(1)
Phase difference between U1(1) and the fundamental current of element 3, I3(1)
max
2 I 2
, I(Total) = (k) ,
k = min
Note
• k denotes a harmonic order, r denotes the real part, and j denotes the imaginary part.
• The minimum harmonic order is denoted by min.
• The upper limit of harmonic analysis is denoted by max. max is determined automatically
according to the PLL source frequency. It can go up to the 50
• The numbers 1, 2, and 3 used in the equations for UΣ, IΣ, PΣ, SΣ, and QΣ indicate the case
when input elements 1, 2, and 3 are set to the wiring system shown in the table.
• Only the total value and the fundamental signal (1
Methods of Computation and Determination
When the denominator of the
distortion factor is the
fundamental signal (Fundamental)
100
•
*1
100
•
*1
100
•
*1
2
100
•
1
*
2
100
•
1
*
100
•
1
*
Three-phase, Three-voltage,
three-wire three-current
3P3W method (3V3A)
P1 + P2
PΣ 2 + QΣ 2
Q1 + Q2
PΣ
SΣ
max
P
P(Total) = (k)
k = min
st harmonic) are computed for Σ.
(Table 2/2)
U(k)
100
•
U(1)
I(k)
100
•
I(1)
P(k)
100
•
P(1)
max
2
U(k)
k = 2
100
•
U(1)
max
2
I(k)
k = 2
100
•
I(1)
max
P(k)
k = 2
100
•
P(1)
Three-phase,
four-wire
3P4W
(U1 + U2 + U3) / 3
(I1 + I2 + I3) / 3
P1 + P2 + P3
Q1 + Q2 + Q3
th
harmonic order.
App-5
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App
Index