Module 7 : Out of Step
Protection
Lecture 25 : Analysis of Power Swings in a Multi – Machine System
The equivalent circuit of fig 25.1 can be reduced as shown in fig 25.2. Now from the equivalent circuit of fig 25.2 we get that,
Therefore, the incremental model is given by,
(5)
Equating (5) to (4) we get,
;
;
; Thus the equivalent circuit is as shown in fig 25.3.
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; 
; 
; Thus the equivalent circuit is as shown in fig 25.3. 
