Sectional Permanent Magnet Generator and Power Electronics For Multi-Megawatt Direct Drive Wind Turbines

79659S As direct drive wind turbines increase in size, the diameter of their generators increases to the point where it is no longer possible to ship them as a single unit. While some companies have addressed this issue by using wound rotor generators that can be assembled on site, this approach suffers from the inherent lower efficiency and reliability of the wound rotor technology. To date, no one has created a sectionalized generator that takes advantage of both the high efficiency and low cost of permanent magnet technology. This project will develop a design for a sectional, permanent magnet generator based on a turbine specification for a variable speed, pitch controlled, direct drive turbine in the 5-7 megawatt size range. In Phase I, a set of generator specifications will be developed that will include generator diameter, air gap size and tolerance, cooling method, power quality and voltage. Several sectional generator designs will be created that meet these specifications, using suitable stator winding and thermal management technologies. Manufacturing and assembly methods will be determined for each design. A modular power converter design will be developed to integrate the output of the generator sections to yield grid-quality output. Commercial Applications and Other Benefits as described by the awardee: The new sectionalized permanent magnet generator design should find use in large commercial wind energy applications. The higher energy capture rate and lower capital cost of these systems would result in cheaper clean electricity, making wind power more widely available. In addition, the fact that these generators can be transported easily means that wind power could be exploited on a large scale in areas that were previously inaccessible