Electrical Power Systems

Let the current in line K be I K1. Let us now define,
AK1 = I K1
I
L
Optimal System Operation 437
...(16.78)
Similarly, ig. 16.11(b) shows that generating station 2 is supplying the total load current.
We can define,
ig. 16.11(b): Generating station 1 is off.
AK2 = I K2
I
L
...(16.79)
where
AK1 and AK2 = current distribution factors.
When both the generators are supplying current into the power network as shown in ig.
16.10, the current in the branch K can be obtained by applying the principle of superposition.
Thus, we can write,
IK = AK1Ig1 + AK2Ig2 ...(16.80)
At this point we will make certain assumptions which are given below:
Assumption-1: or all network branches ratio X
is same.
R
Assumption-2: All the load currents have the same phase angle. To understand this
consider bus i of the network as shown in ig. 16.12.
rom ig. 16.12, we can write
ig. 16.12: Bus i of the power network.
I Li =
PL - jQL
i i
Vi
*
=
H
PL + QL
V
2
i
-d
i i
2
i
I
K
-f i