Siemens SIMEAS R-PMU, Руководство пользователя, Страница: 48 / 296

6
6.3 Calculating Derived Values
48
Digital Fault Recorder, SIMEAS R-PMU, Manual
E50417-H1076-C360-A5, Release 10.2012
6.3.2 Symmetrical Components
Star connection: phase-to-earth voltages and currents
With and :
Positive-sequence system:
Negative-sequence system:
Zero-sequence system
:
a
e
j
2
Π
3
⁄ ( )
= a
2
e
j
2 –
Π
3
⁄ ( )
=
V
1
1
3
---
V
L1
a V
L2
a
2
V
L3
⋅
+
⋅
+
( ) ⋅
=
I
1
1
3
---
I
L1
a I
L2
a
2
I
L3
⋅
+
⋅
+
( ) ⋅
=
V
2
1
3
---
V
L1
a
2
V
L2
a V
L3
⋅
+
⋅
+
( ) ⋅
=
I
2
1
3
---
I
L1
a
2
I
L2
a I
L3
⋅
+
⋅
+
( ) ⋅
=
V
0
1
3
---
V
L1
V
L2
V
L3
+ +
( ) ⋅
=
I
0
1
3
---
I
L1
I
L2
I
L3
+ +
( ) ⋅
=
Note
‰
The Continuous RMS-value Recorder (CRR) only records the absolute value of the
symmetrical components.
‰
Triggering is also done using only the absolute value of the symmetrical components.
‰
The PMU transfers the positive-sequence system as complex values!