Digital Controller Design via LMIs for Direct-Driven Surface Mounted PMSG-Based Wind Energy Conversion System.

The main concern of this paper is to design the efficient sampled-data controller scheme that resolves the stabilization issue of a surface-mounted permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS). Distinct to the existing controller schemes on WECS, the present scheme contains both continuous (plant) and discrete (control) type of signals which outperforms the traditional scheme with continuous or discrete signals. Besides that the fundamental analysis of the closed-loop system under the designed controllers explore the dynamical characteristics of the considered PMSG-based WECS. The stability and stabilization of the proposed closed-loop system have guaranteed through the Lyapunov stability theory and solvable linear matrix inequalities (LMIs). In detail, first, the nonlinear PMSG model has equivalently expressed into linear submodels via the Takagi-Sugeno (T-S) fuzzy approach based on suitable membership rules. Second, the sufficient conditions have been derived as LMIs that ensure the stability and stabilization of the formulated T-S fuzzy PMSG-based WECS. Finally, the effectiveness of the designed controller as well as the consistency of sufficient conditions has demonstrated through numerical evaluations of the closed-loop system.