13.8 Calculation Formula
235
10
13
Chapter 13 Specifications
Voltage zero-phase component Uzero [V]
The fundamental RMS voltage (phase voltage) from harmonic calculations is used for U1, U2, and U3.
For 3-phase 3-wire connections, the value is detected as a line voltage and the
n converted to a phase voltage.
At the zero-phase, seq2=0°, seq3=0°
α=U1 p
hase angle, β=U2 phase angle, γ=U3 phase angle
Voltage positive-phase component Upos [V]
The fundamental RMS voltage (phase voltage) from harmonic calculations is used for U1, U2, and U3.
For 3-phase 3-wire connections, the value is detected as a line voltage and the
n converted to a phase voltage.
At the positive-phase, seq2=120°, seq3=240°
α=U1 p
hase angle, β=U2 phase angle, γ=U3 phase angle
Voltage negative-phase component Uneg [V]
The fundamental RMS voltage (phase voltage) from harmonic calculations is used for U1, U2, and U3.
For 3-phase 3-wire connections, the value is detected as a line voltage and the
n converted to a phase voltage.
At the negative-phase, seq2=240°, seq3=120°
α=U1 p
hase angle, β=U2 phase angle, γ=U3 phase angle
-6. Voltage unbalance factor, Current unbalance factor
Single
Phase
2-wire
1P2W
Single
Phase
3-wire
1P3W
3-Phase, 3-Wire,
2-Measurement
3P3W2M
3-Phase, 3-Wire,
3-Measurement
3P3W3M
3-Phase, 4-Wire
3P4W
Voltage
unbalance factor
Uunb0 [%]
Voltage
unbalance factor
Uunb [%]
Same as 3P3W3M
(U
31
is computed by
means of vector calcula-
tions.)
where where
•For U
12
, U
23
, and U
31
, use the fundamental wave RMS voltage from the calculated harmonics results.
• For three-phase 4-wire configurations, this is detected using pha
se-to-neutral voltage but can be converted and
calculated using line-to-line voltage.
Current
unbalance factor
Iunb0 [%]
Current
unbalance factor
Iunb [%]
Same as 3P3W3M
(I
31
is computed by
means of vector calcula-
tions.)
where where
•For I
12
, I
23
, and I
31
, use the fundamental wave RMS current (line-to-line current) from the calculated harmonics
results.
• For three-phase 3-wire and three-phase 4-wire configurations
this is detected using phase current, but can be con-
verted and calculated using line-to-line current.
Uunb0
Uzero
Upos
----------------
100×=
Uunb0
Uzero
Upos
----------------
100×=
Uunb0
Uzero
Upos
----------------
100×=
Uunb
136β––
136β–+
----------------------------- 100×=
β
U
4
12
U
4
23
U
4
31
++
U
2
12
U
2
23
U
2
31
++
2
--------------------------------------------=
Uunb
136β––
136β–+
----------------------------- 100×=
β
U
4
12
U
4
23
U
4
31
++
U
2
12
U
2
23
U
2
31
++
2
--------------------------------------------=
Iunb0
Izero
Ipos
----------------
100×=
Iunb0
Izero
Ipos
----------------
100×=
Iunb0
Izero
Ipos
----------------
100×=
Iunb
136β––
136β–+
----------------------------- 100×=
β
I
4
12
I
4
23
I
4
31
++
I
2
12
I
2
23
I
2
31
++
2
--------------------------------------------=
Iunb
136β––
136β–+
----------------------------- 100×=
β
I
4
12
I
4
23
I
4
31
++
I
2
12
I
2
23
I
2
31
++
2
--------------------------------------------=
Uzero
1
3
---
U1 α()cos• U2 β seq2+()cos• U3 ϒ seq3+()cos•++()
2
U1 α()sin• U2 β seq2+()sin• U3 ϒ seq3+()sin•++()
2
+
=
Upos
1
3
---
U1 α()cos• U2 β seq2+()cos• U3 ϒ seq3+()cos•++()
2
U1 α()sin• U2 β seq2+()sin• U3 ϒ seq3+()sin•++()
2
+
=
Uneg
1
3
---
U1 α()cos• U2 β seq2+()cos• U3 ϒ seq3+()cos•++()
2
U1 α()sin• U2 β seq2+()sin• U3 ϒ seq3+()sin•++()
2
+
=
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