These are two books:

1. Michael J. Grimble,"Robust Industrial Control-optimal design approach for polynomial systems, Prentice \\hall,

2. Iulian Munteanu, "Optimal Control of Wind Energy Systems-Towards a Global Approach, Springer

Thanks a lot for your answer. I'll try to check the books.

I agree with Rami Maher in recommending the book -Iulian Munteanu, "Optimal Control of Wind Energy Systems-Towards a Global Approach, Springer.

There are lot of recent papers in this title in Science Direct which will help u much

I actually got the book from our library and now reading it. I also found below mentioned review in IEEE Control Magazine which says there is not much organised discussions in the book on blade pitch control in this book. Nonetheless, I'll read it to get a understanding of the basic ideas in wind turbine control.

http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=04939314

Vahid....We authored a paper on pitch angle regulation (Plz see my publications list if you are interested)

Ibrahim, thanks for letting me know. I'll check your publications.

The opensource program "FAST" can help you with the PID controller in the Fortran Program source available here: 

https://nwtc.nrel.gov/Seismic

also for blade pitch analysis I've done some work on the effects of pitch control, not going into the control itself:

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1858144

http://iopscience.iop.org/article/10.1088/1742-6596/524/1/012062?fromSearchPage=true

regards

http://web.mit.edu/windenergy/windweek/Presentations/P9%20-%20Lackner.pdf