VAMP 59 - Symmetric Components

4.8 Symmetric components
4 Measurement functions
Technical description
136
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VM59.EN001
4.8. Symmetric components
In a three phase system, the current phasors may be divided in
symmetric components according C. L. Fortescue (1918). The
symmetric components are:
 Positive sequence 1
 Negative sequence 2
 Zero sequence 0
Symmetric components are calculated according the following
equations:































W
V
U
aa
aa
S
S
S
2
2
2
1
0
1
1
111
3
1
, where
S
0
=
zero sequence component
S
1
=
positive sequence component
S
2
=
negative sequence component
2
3
2
1
1201 ja 
, a phasor rotating constant
U
=
phasor of phase L1 (phase current)
V
=
phasor of phase L2
W
=
phasor of phase L3