Type-2 fuzzy based adaptive synergetic power system control

This paper introduces a new type-2 fuzzy based adaptive synergetic power system stabilizer used in damping power flow limiting oscillations that often occur following disturbances in power systems. Small magnitude and low frequency oscillations, linked to the electromechanical modes in power systems, often persist for long periods of time leading in some cases to loss of synchronism and eventually to blackouts. These oscillations may occur locally or between different areas of a power system. Among many robust control techniques to assure service continuity sliding mode has been proposed despite its inherent chattering drawback. This paper present a novel power system stabilizer based on synergetic control which possesses the same strong robustness and invariance to external disturbances as sliding mode but without its negative chattering. Type-1 fuzzy systems have also been heavily relied on to describe unknown system model but they lack fuzziness in dealing with uncertainties. Better suited to deal with uncertainties type-2 fuzzy systems are used in this paper in approximating the unknown power system nonlinear dynamics while stability is insured through Lyapunov synthesis. Severe operating conditions are used in a simulation study to test the validity and effectiveness of the proposed method. Results indicate good performance and satisfactory transient dynamic behaviour. A multi-machine power system is used to demonstrate the performance of the proposed controller and to show its superiority over other conventional stabilizers used in the literature.

► A new type-2 fuzzy based adaptive synergetic power system stabilizer.
► A novel power system stabilizer based on synergetic control which possesses the same strong robustness and invariance to external disturbances as sliding mode but without its negative chattering.
► The robustness is verified on a single-machine infinite-bus and on a multi-machine power system stabilizer.
► A comparative simulation study is presented over a conventional, an adaptive fuzzy and a sliding mode power system stabilizers.