Application of Multi-Objective Gravitational Search Algorithm (GSA) for Power System Stability Enhancement by Means of STATCOM

摘要

In this paper, on the basis of the theoretical analysis of a single-machine infinite-bus (SMIB), using its modified linearized Phillips-Heffron model installed with STATCOM, the potential of the STATCOM supplementary controller to enhance the dynamic stability of a power system is evaluated by measuring the electromechanical controllability through singular value decomposition (SVD) analysis. This controller is tuned to simultaneously shift the undamped electromechanical modes to a prescribed zone in the s-plane. The problem of robustly STA TCOM based damping controller is formulated as an optimization problem according to the eigenvalue-based multi-objective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using gravitational search algorithm (GSA) that has a strong ability to find the most optimistic results. To ensure the robustness of the proposed damping controller, the design process takes into account a wide range of operating conditions. The effectiveness of the proposed controller is demonstrated through controllability measure, eigenvalue analysis and some performance indices studies. The different loading conditions are simulated on a single-machine infinite-bus system and the rotor speed deviation, internal voltage deviation, DC voltage deviation and electrical power deviation responses are studied with the effect of this FACTS controller. The results analysis reveals that the tuned GSA based STATCOM controller using the proposed multi-objective function has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems.