Acknowledgments

Book writing is a systematic exercise in compiling the ideas into a coherent field of knowledge. It is with immense pleasure I place on record my gratitude towards the inspiration and motivation received from Prof. S. Ramachandram, Vice-Chancellor, Osmania University, Hyderabad, India. I wish to express my sincere thanks to Prof. S. Sameen Fatima, Principal, University College of Engineering, Prof. P.V.N. Prasad, Director CD&AAC and Dr. B. Mangu, Head, Department of Electrical Engineering. I am grateful to my research supervisors Prof. S.V.L. Narasimham and Late Prof. J. Amarnath, Jawaharlal Nehru Technological University Hyderabad for their continuous support during my Ph.D. study and related research.

I also take great honour to acknowledge the support of my teachers who have taught me through various courses from school to university level. I also thank all the faculty members of Electrical Engineering Department, UCE, OU for their support and valuable suggestions.

I also thank Prof. V. Appa Rao, Controller of Examinations, OU and Prof. J.L.N. Rao, Addl. Controller of Examinations and Prof. S. Ramakrishna for their support and encouragement. I would like to thank Mr. M. Satyanarayana, Research Assistant for his valuable help in the preparation of manuscript, editing and publishing the book.

I would like to express my appreciation for the loving support I have received from my mother Aruna, my wife Roja Rani, my children Sudhamsh-Sudheshna, and my extended family members Venu Kumar, Jayasri, Kishan and Uma Rani.

Finally, I also wish to express my deep sense of gratitude to my friends and all those who helped me directly or indirectly in the completion of this book.