TABLE OF CONTENTS The main purpose here is to explain the technology in common use for large-scale wind power generation. The evolution of turbine design is first of all placed in its historical context. The current design choices facing the industry are then considered. A simple analysis of the basic process of wind energy extraction is presented, leading to a discussion of the critical area of power regulation. It will be seen that the options here depend on whether fixed- or variable-speed technology is adopted.
The description of fixed-speed wind turbine technology includes a review of relevant induction machine theory. The induction (or asynchronous) machine is a key component of fixed-speed wind generators, as well as forming the basis for partial variable-speed designs. This section considers some of the shortcomings of the fixed-speed designs which dominated the industry s initial growth surge.
The final section of the chapter reviews the arguments that have led to the growing dominance of variable-speed technology. The section includes a detailed treatment of partial variable-speed (doubly fed induction generator [DFIG]) and full variable-speed wind turbine generator configurations.
The wind has been used as a source of power for pumping water and grinding corn for more than a thousand years and, by the eighteenth century, the traditional European windmill had evolved into a sophisticated device capable of developing up to 25 kW in strong wind (Golding, 1955). It is estimated that before the industrial revolution there were some 10,000 windmills in...
