An LMI Approach to Fuzzy pole cluster for Regulating Wind Energy Conversion System

This paper addresses the design of fuzzy state feedback controller that has not only the ability to stabilize the fuzzy model/system but also to control the transient behavior and closed loop pole location for wind energy conversion system which present interesting control demands and exhibits intrinsic nonlinear characteristics. The proposed fuzzy controller is employed to regulate indirectly the power flow in the DC link by regulating the DC current. First, a Takagi-Sugeno fuzzy model is employed to represent a nonlinear system. Then a model-based fuzzy controller design utilizing the concept of parallel distributed compensation is developed. Additional constraints on the closed loop pole location are satisfied. Satisfactory time response and closed loop damping are achieved by forcing the closed loop poles into a suitable sub-region of the left half plane. These conditions are expressed in terms of linear matrix inequalities (LMI´s) which can be solved very efficiently using convex optimization techniques. The design techniques are applied to a dynamic model of wind energy conversion system to illustrate the feasibility of the proposed solution