FUZZY LOGIC BASED INTELEGENT CONTROL OF A WIND GENERATION SYSTEM

Abstract-The paper describes a variable speed wind generation system where fuzzy logic principles are used for efficiency optimization and performance enhancement control. A squirrel cage induction generator feeds the power to a double-sided pulse width modulated converter system which pumps power to a utility grid or can supply to an autonomous system. The generation system has fuzzy logic control with vector control in the inner loops. A fuzzy controller tracks the generator speed with the wind velocity to extract the maximun power. A second fuzzy controller programs the machine flux for light load efficiency improvement. and a third fuzzy controller gives robust speed control against wind gust and turbine oscillatory torque. The complete control system has been developed, analyzed. and validated by simulation study. Performances have then been evaluated In detail.


INTRODUCTION
A WIND electrical generation system is the most cost- competitive of all The environmentally clean and safe renewable energy sources in the world. lt is also competitive with fossil fuel generated power and much cheaper than nuclear power. Although the history of wind power goes back more than two centuries. Its potential to generate electrical power began to get attention from the beginning or this century. However, during the last two decades, wind power has been seriously considered to supplement the power generation by fossil fuel and nuclear methods. In recent years. wind power is gaining more acceptance because or environmental and safely problems of conventional power plants and advancement of wind electric generation technology. The world has enormous resources of wind power. It has been estimated that even if 10% of raw wind potential could be put to use, all the electricity needs of the world would be met [1]. There are currently over 1700 Mw or wind generators installed worldwide with generation of 6 billion kWh of energy annually. It has been estimated the generation will grow to 60 billion kWh by the year 2000. Of course, the main drawback of wind power Is that its availability is somewhat statistical in nature and must be supplemented by additional sources to supply the demand curve.

FUZZY LOGIC CONTROLL

The System has three fuzzy logic controllers.

A. Generator Speed Tracking Control (FLC-1)

B. Generator Flux Programing Control (FLC-2)

C. Close-Loop Generation Speed Control (FLC-3)

CONCLUSION

A complete fuzzy logic control based wind generation system has been described in the paper. The system was analyzed and designed. and performances were studied extensively by simulation to validate the theoretical concepts. The experimental work is in progress and will be reported later. There are three fuzzy logic controllers in the system. Controller FLC-l searches on-line the optimum generator speed so that aerodynamic efficiency or the wind turbine is optimum. A second fuzzy controller FLC-2 programs The machine flux by an on-line search so as to optimize the machine-converter system efficiency. A third fuzzy controller F1C-3 performs rob bust speed control against turbine oscillatory torque and wind vortex. Advantages or fuzzy control are that it is parameter insensitive, provides fast convergence, and accepts noisy and inaccurate signals. The fuzzy algorithms are universal and can be applied retroactively in any system. System performance. both in steady state and dynamic conditions, was found to be excellent.


Adapted From : IEEE Journal & Public