07-10-2010, 11:32 AM
This article is presented by:
Satish J Ranade
Classical Analysis
Equal Area Criterion
Power System Dynamics and Transients
A generator connected to an infinite bus through a line. Initially Pm=PeStability is governed by the Swing Equation
d2δ/dt2 = (πf/H) (Pm-Pe)
dδ /dt = ω-ωsyn
Swing Equation
Power Angle
Equation
Pe = E’ V sin (δ) /(X+XL)
First swing stability-Equal Area Criterion
Stable Equilibrium—small increase in mechanical power
At D ω is decreasing but > 0
δ increases further say to point E
By now suppose ω is back to zero and decreasing
Thus ω becomes < 0 as the generator continues to slow
Since ω<0 δ decreases towards B First swing stable!
For more information about this article,please follow the link:
http://ece.nmsu.edu/~sranade/EE532_06_8.ppt