Wind Energy Conversion.- Modern Power Electronics and Converter Systems.- Generator Systems for Wind Turbines.- Control of Wind Turbines.- Electrical Topologies of Wind Farms Based on Different Wind Turbines.- Integration of Wind Turbines into Power Systems.- Conclusion.

Frede Blaabjerg was born in Erslev, Denmark, on May 6, 1963. He received the M.Sc.EE. from Aalborg University, Denmark in 1987, and the Ph.D. degree from the Institute of Energy Technology, Aalborg University, in 1995. He was employed at ABB-Scandia, Randers, from 1987 to 1988. During 1988-1992 he was a Ph.D. student at Aalborg University. In 1992, he became an Assistant Professor at Aalborg University, in 1996 an Associate Professor, and in 1998 Professor in power electronics and drives. In 2000, he was a Visiting Professor at the University of Padova, Italy, as well as part-time programme research leader at Research Center Risoe. In 2002, he was a Visiting Professor at Curtin University of Technology, Perth, Australia. His research areas include power electronics, static power converters, ac drives, switched reluctance drives, modelling, characterization of power semiconductor devices and simulation, power quality, wind turbines, and green power inverter. He is involved in more thanfifteen research projects with the industry. Among these has been the Danfoss Professor Programme in Power Electronics and Drives. He is the author or coauthor of more than 500 publications in his research fields including the book Control in Power Electronics (edited by M.P. Kazmierkowski, R. Krishnan, F. Blaabjerg) published by Academic Press in 2002. Dr. Blaabjerg is a member of the European Power Electronics and Drives Association and the IEEE Industry Applications Society Industrial Drives Committee. He is also a member of the Industry Power Converter Committee and the Power Electronics Devices and Components Committee in the IEEE Industry Application Society. He is the Associated Editor of the IEEE Transactions on Industry Applications, IEEE Transactions on Power Electronics, Journal of Power Electronics, and of the Danish journal Elteknik. He is also Editor-in-Chief of IEEE Transactions on Power Electronics. Frede Blaabjerg was born in Erslev, Denmark, on May 6, 1963. He received the M.Sc.EE. from Aalborg University, Denmark in 1987, and the Ph.D. degree from the Institute of Energy Technology, Aalborg University, in 1995. He was employed at ABB-Scandia, Randers, from 1987 to 1988. During 1988-1992 he was a Ph.D. student at Aalborg University. In 1992, he became an Assistant Professor at Aalborg University, in 1996 an Associate Professor, and in 1998 Professor in power electronics and drives. In 2000, he was a Visiting Professor at the University of Padova, Italy, as well as part-time programme research leader at Research Center Risoe. In 2002, he was a Visiting Professor at Curtin University of Technology, Perth, Australia. His research areas include power electronics, static power converters, ac drives, switched reluctance drives, modelling, characterization of power semiconductor devices and simulation, power quality, wind turbines, and green power inverter. He is involved in more than fifteen research projects with the industry. Among these has been the Danfoss Professor Programme in Power Electronics and Drives. He is the author or coauthor of more than 500 publications in his research fields including the book Control in Power Electronics (edited by M.P. Kazmierkowski, R. Krishnan, F. Blaabjerg) published by Academic Press in 2002. Dr. Blaabjerg is a member of the European Power Electronics and Drives Association and the IEEE Industry Applications Society Industrial Drives Committee. He is also a member of the Industry Power Converter Committee and the Power Electronics Devices and Components Committee in the IEEE Industry Application Society. He is the Associated Editor of the IEEE Transactions on Industry Applications, IEEE Transactions on Power Electronics, Journal of Power Electronics, and of the Danish journal Elteknik. He is also Editor-in-Chief of IEEE Transactions on Power Electronics.

Wind energy is now the world's fastest growing energy source. In the past 10 years, the global wind energy capacity has increased rapidly. The installed global wind power capacity has grown to 47.317 GW from about 3.5 GW in 1994. The global wind power industry installed 7976 MW in 2004, an increase in total installed generating capacity of 20%. The phenomenal growth in the wind energy industry can be attributed to the concerns to the environmental issues, and research and development of innovative cost-reducing technologies. Denmark is a leading producer of wind turbines in the world, with an almost 40% share of the total worldwide production. The wind energy industry is a giant contributor to the Danish economy. In Denmark, the 3117 MW (in 2004) wind power is supplied by approximately 5500 wind turbines. Individuals and cooperatives own around 80% of the capacity. Denmark will increase the percentage of energy produced from wind to 25% by 2008, and aims for a 50% wind share of energyproduction by 2025. Wind technology has improved significantly over the past two decades, and almost all of the aspects related to the wind energy technology are still under active research and development. However, this monograph will introduce some basics of the electrical and power electronic aspects involved with modern wind generation systems, including modern power electronics and converters, electric generation and conversion systems for both fixed speed and variable speed systems, control techniques for wind turbines, configurations of wind farms, and the issues of integrating wind turbines into power systems. P