Acknowledgement
I would first like to thank my thesis advisor Prof. Saponara of the faculty of engineering at University of Pisa. He was always available whenever i need his support. Also is important for me to thank the Pure Power Control s.r.l. specially Eng. Mazzi for accept and involve me in his group of work giving me the tools to reach the objectives.
Profound gratitude to my mother Luz Angela Ramírez Lugo for providing me with unfailing support and continuous encouragement throughout my years of study and through the process of researching and writing this thesis. This accomplishment would not have been possible without her. Thank you.
Is appropriate to thanks my colleagues that make this period of my life peaceful and bearable. Finally i would like to thanks all my friends of Pisa that create the best ambient to enjoy these years at the University specially to my unconditional friend José.
Author
Gianfranco Serecchia Ramirez.