A fuzzy-logic based control strategy for maximum efficiency of a Wind Energy Conversion System

In this paper, a control method for a Wind Energy Conversion System (WECS) utilizing a Squirrel Cage Induction Generator (SCIG) is presented. Aims of the control are both maximum wind power harvesting and minimization of the SCIG power loss, thus achieving maximum power production on any wind speed. The SCIG is connected to the utility grid through two back-to-back converters. The first converter uses Field Oriented Control to regulate the speed and the excitation of the SCIG. The proposed control system uses two Fuzzy-Logic Controllers that regulate the speed and excitation of the SCIG, implementing Maximum Power Point Tracking (MPPT) and Loss Minimization by regulating the speed of the generator and the excitation respectively. Thus, maximum power is extracted by the wind and additionally, power output is increased by reducing the core loss of the generator. In order to improve the slow response time of the flux-linkage to the d-axis current an additional control loop has been introduced that improves the response time of the flux-linkage. Several experimental results are displayed that validate the operational improvements of the proposed control scheme.