Fuzzy logic based indirect vector control of induction generator in Wind Energy Conversion System

Abstract

In order to meet increasing power demand, taking into account economical and environmental factors, wind energy conversion is gradually gaining interest as a suitable source of renewable energy. The modeling of Wind Energy Conversion System(WECS) is done in MATLAB-SIMULINK. The dynamic d-q model of the induction generator is developed from the fundamentals in a modular approach in simulink. A fuzzy logic controller is designed for indirect vector control of induction generator. The vector control or field oriented control of induction motor and synchronous motors brought a renaissance in the high performance control of ac drives. In the vector control, the induction motor can be controlled like a separately excited dc motor. In a separately excited dc motor, because of decoupling, when the field current If is controlled, it affects the field flux only but not the armature flux. Thus giving fast transient response in the dc drive. Because of the inherent coupling problem, an induction motor cannot give such a fast response. The dc machine like performance can also be extended to induction motor if the machine control is considered in the synchronously rotating reference frame (de-qe), where the sinusoidal variables appear as dc quantities in steady state. The speed control loop uses a fuzzy logic controller to produce a direct axis current reference Id* which controls the motor flux. The motor torque is controlled by quadrature axis current reference Id*. The correctness and effectiveness of the proposed fuzzy logic controller are verified by the simulation results.