An Adaptive Controller for Improving Dynamic Stability of Synchronous Power System

Abstract

This paper presents a new adaptive control approach for improving dynamic stability of power systems. The adaptive control structure is based on hyperstability theory. The design method of the closed loop system does not need the specification of weighting matrices. The eigenvalues of electromechanical mode of the system is shifted to a prespecified vertical strip. The control is constructed so that the closed loop system is hyperstable, guaranteeing the dynamic stability improvement of power systems. The changeable gains generated specifically but not uniquely by a nonlinear time varying function act as adaptive mechanism. Compared with MRAC or STAC, the proposed control structure avoids the difficulty of choosing an appropriate reference model and the burden of implementing an online parameter estimator. The power system under investigation consists of a synchronous machine connected to an infinite bus. It has both voltage regulator and speed governor controls. The effectiveness of the controller for damping machine oscillations caused by power system disturbances is verified by simulation studies.