Comparison with the real
situation, excluding of sudden change phenomena such
shadow effect, fault condition or islanding effect, the weather
conditions, load and utility are slightly change comparing to
the time. Then small disturbance stability or small signal
stability with linear theory can be applied in this study. There
are several type of linear stability method such as Right hand
plane (RHP), root locus, Routh – Hurwitz criterion, Z plane
and Unit circle, Eigenvalue of Jacobian matrix, Lyapunov
and Bode-Nyquist stability criterion