Foreword

During the past decade, the installed wind power capacity in the world has been increasing more than 30%. Wind energy conversion system (WECSs) based on the doubly-fed induction generator (DFIG) dominated the wind power generations due to the outstanding advantages, including small converters rating around 30% of the generator rating, lower converter cost.

Due to the non-linearity of wind system, the DFIG power control presents a big challenge especially under wind-speed variation and parameter’s sensibility.

To overcome these major problems; an improved IDPC (Indirect Power Control); based on PID “Proportional-Integral-Derivative” controller, was proposed instead the conventional one (based on PI), in order to enhance the wind-system performances in terms; power error, tracking power and overshoot. Unfortunately using robustness tests (based on severe DFIG’s parameters changement); the wind-system offers non-satisfactory simulation results which were illustrated by the very bad power tracking and very big overshoot (> 50%).

In this context; adaptive, robust & intelligent controllers were proposed to control direct & quadrature currents (Ird & Irq) under MPPT (Maximum Power Point Tracking) strategy to main the unity power factor (PF≈1) by keeping the reactive power at zero level. In this case, the new IDPC based on intelligent controllers offered an excellent wind-system performance especially using robustness tests, which offered a big improvement especially using Type-1 Fuzzy Logic Controller (T1-FLC), Type-2 Fuzzy Logic Control (T2-FLC; is the New class of fuzzy logic) & Neuro-Fuzzy Logic (NFC).

In this sense, I think that this edited book is an important contribution to help students already in mastery of the basis of power electronic circuits and control systems theory to achieve these pedagogical goals. The proposed book describes with easy manner the modeling & control of Wind-turbine DFIG in order to control the stator powers using different topologies of robust, adaptive and intelligent controllers.

The book present numerous intelligent control techniques that help in the control design of the DFIG wind-system (WT).

The textbook “Improved Indirect Power Control (IDPC) of Wind Energy Conversion Systems (WECS)” proposes a collection of concepts, organized in a synergic manner such that to ease comprehension of the WT control design.

The book’s contribution goes towards completing the already existing literature by offering a useful integration of control techniques, worthy to be read, understood and employed in the various WT applications.

Please enjoy reading this book.