Fuzzy logic based control of variable speed cage wind generation system

Abstract

The global electrical energy consumption is rising and their is steady increase of the demand on power generation. So in addition to conventional power generation units, a large no. of renewable energy units are being integrated into the power system. A wind electrical generation system is the most cost competitive of all the environmentally clean and safe renewable energy sources in the world. The recent evolution of power semiconductors and variable frequency drive technology has aided the acceptance of variable speed generation systems. Fuzzy logic is a powerful and versatile tool for representing imprecise, ambiguous and vague information. It helps us model difficult, even intractable problems. Advantages of fuzzy control are that it is parameter insensitive, provides fast convergence and accepts noise noisy and inaccurate signals. The fuzzy algorithms are universal and can be applied retroactively in any system. In this thesis a squirrel cage induction generator feeds power to a double sided pulse width modulated converter system which feeds power to an autonomous load or grid. The generation system has three no.s of fuzzy logic control with vector control in its inner loop.
* The first fuzzy controller tracks the generator speed with the wind velocity to extract maximum power.
* The second fuzzy controller programs the machine flux for light load efficiency improvement.
* The third fuzzy controller gives robust speed control against wind gust and turbine oscillatory torque.
The fuzzy logic based control of the system helps to optimize efficiency and enhance performance. The system gives excellent performance and can easily be translated to a larger size in the field.