Siemens SIMEAS R - Symmetrical Components

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 2Π 3⁄()
=
a
2
e
j 2– Π 3⁄()
=
V
1
1
3
---
V
L1
aV
L2
a
2
V
L3
⋅+⋅+()⋅=
I
1
1
3
---
I
L1
aI
L2
a
2
I
L3
⋅+⋅+()⋅=
V
2
1
3
---
V
L1
a
2
V
L2
aV
L3
⋅+⋅+()⋅=
I
2
1
3
---
I
L1
a
2
I
L2
aI
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!