262
Practical MATLAB
® Applications for Engineers
R.3.77 3 Φ Systems are the most common confi gurations used to generate and deliver
electrical power. A 3 Φ system, with sequence ABC is shown in Figure 3.42, where
the sequence label indicates the generation path.
R.3.78 The line voltages are the voltages V AN , V BN , and V CN .
R.3.79 The system voltages are referred to as the voltage between any pair of line voltages
such as V AB , V BC , and V CA .
FIGURE 3.39
Single-phase system.
V
V AB
0 °
V
V BC
0 °
A
B
C
V
V AC
0 °
2
0 °
V
FIGURE 3.40
Two-phase system.
I
l
E 1 = E 0 ° V
E 1 = E 90 ° V
Z L
Z L
Z N
Z 1
Z 2
1
2
N
I 1
I 2
I N
FIGURE 3.41
Phasor diagram of Figure 3.40.
E
E 12
45 °
2
−
∠
=
E
E 2
90 °
∠
=
45 °
E
E 1
0 °
∠
=
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7/23/2008 1:27:41 PM
7/23/2008 1:27:41 PM