A SFOC-based scheme with PI-ANN controller to regulation of output powers and reduction of current harmonics for DFIG under unbalanced voltage dips

Abstract

This paper presents a newly modified control scheme using artificial neural network (ANN) for doubly fed induction generator (DFIG) connected with a wind turbine under the unbalance of three-phase grid voltages. In detail, the proposed scheme is based on the stator flux oriented control (SFOC), and it consists of a Sequence Component controller (SCC) and a unique PI with ANN (PI-ANN) hybrid controller. The main objectives of the suggested scheme are to regulate independently the output active and reactive powers of DFIG and to diminish significantly harmonics in the rotor current during the unbalanced grid voltage dips. Numerical simulations, including considerations on sudden changes of reference values for the powers and the random alteration of wind speed, are performed in MATLAB to evaluate effectiveness of the proposed scheme. Furthermore, detailed comparisons between simulation results under the unbalanced voltage dips, obtained with the traditional PI method, PI with fuzzy logic (PI-F) hybrid technique and suggested PI-ANN scheme, also are illustrated to validate the salient performance of the presented control structure.