Analysis, Modeling and Control of Doubly-Fed Induction Generator for Wind Turbines

Abstract

In recent years, wind energy has become one of the most important and promising sources of renewable energy. In order to meet power needs, taking into account economical and environmental factor, wind energy conversion is gradually gaining interests as a suitable source of renewable energy. This dissertation deals with the analysis, modeling, and control of the doubly-fed induction generator (DFIG) for wind turbines. The stator of the generator is directly connected to the grid while the rotor is fed at variable frequency through the AC-CD-AC converter and a mathematical model of the machine is written in appropriate d-q reference frame is established to investigate simulation. This dissertation also presents the simulation of wind turbine drives doubly-fed induction generator. Two voltage source converters are used to extract maximum power from variable wind speed. The grid-side converter controls the power flow between the DC bus and the AC side. The rotor-side converter control the output power generated. Matlab/Simulink software is used to simulate the system. The results of three wind speed are obtained and compared.