A nonlinear voltage controller based on interval type 2 fuzzy logic control system for multimachine power systems

In this paper, we propose an interval type-2 fuzzy controller that has the ability to enhance the transient stability and achieve voltage regulation simultaneously for multimachine power systems. The design of this controller involves the direct feedback linearization (DFL) technique. The DFL compensated system model is transformed into an equivalent type 1 T–S fuzzy model using linearly independent functions. This paper highlights the mathematical foundations for analyzing the stability and facilitating the design of stabilizing controllers of the interval type 2 Takagi–Sugeno fuzzy control systems (IT2 T–S FLCSs). Sufficient conditions for designing the interval type-2 fuzzy controller with meeting quadratic D stability constraints are obtained by using Linear Matrix Inequalities (LMIs). Based on only local measurements, the designed controller guarantees transient stability, voltage regulation and satisfies desired transient responses. The proposed controller is applied to two-generator infinite bus power system. Simulation results illustrate the performance of the developed approach regardless of the system operating conditions.

► An interval type 2 fuzzy controller is proposed. ► This controller achieves the transient stability and voltage regulation. ► The dynamic model of power system is presented by T1 TS fuzzy model. ► The synthesis of the IT2 fuzzy controller is under pole placement constraints. ► The control tasks are reformulated as convex optimization problems with LMI.