Modeling and control of autonomous Wind Energy Conversion System with Doubly Fed Induction Generator

This paper deals with the modeling and control of a three phase four wire autonomous Wind Energy Conversion System (AWECS) using Doubly Fed Induction Generator (DFIG) feeding local loads. It presents a procedure for design and selection of the components and a vector control algorithm for AWECS. The proposed control algorithm for AWECS is realized using back to back connected Pulse Width Modulated (PWM) Insulated Gate Bipolar Transistors (IGBTs) based voltage source converters (VSCs) with a battery energy storage system (BESS) at their dc link. The main objectives of the control algorithm are maximum power tracking (MPT) through rotor speed control, and voltage and frequency control (VFC) at the stator terminals of the DFIG under dynamic electrical and mechanical conditions. A zigzag transformer is used between stator side converter and the stator for harmonic elimination, optimum selection of the voltage of dc link and providing the neutral terminal for the three phase four wire system. The proposed electro-mechanical system is modeled and simulated in MATLAB using Simulink and Sim Power System (SPS) set toolboxes. The performance of the proposed AWECS is presented to demonstrate its capability of MPT, VFC at stator terminals, harmonic elimination, load balancing and load leveling.