An Improved Automatic Load Frequency Controller for Damping Low Frequency Power Oscillations

Abstract

This paper presents a mathematical formulation of a centralised controller for damping the unwanted oscillations in power systems. The proposed approach assumes a linearised model of the power system around an operating point and makes intensive use of the eigenstructure of the state matrix. The proposed algorithm accurately computes the unstable and poorly damped modes and determines the system components most involved in these critical modes, and damps all undamped modes simultaneously in an acceptable time. Simulation results in a two-area power system indicate that all unwanted oscillations due to a 1% step load change are damped when the controller is used. Validity and effectiveness of the proposed controller are demonstrated by comparing the obtained results with results of previously reported approaches