Identification of electromechanical oscillations using small-signal stability assessment : a case study of Lakvijaya power station

Abstract

Lakvijaya power plant is the biggest power plant in Sri Lanka contributing more than 50% of power annually to the national grid. The main objective of this thesis is to study of the electromechanical oscillations of Lakvijaya Power Plant using small-signal stability assessment. Small signal stability problem refers to the stability problems caused by small disturbances. For small-signal stability studies, the power system can be represented as a linearized state space model. An algorithm is developed in MATLAB using detailed models of synchronous generators, transmission lines and the associated controls. The eigenvalues and eigenvectors of the dynamic state matrix are obtained to study small signal stability. The mode shape calculation is used to identify the dominant oscillations in the system.