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

Wind power has the potential of supplying a significant percentage of the United States electrical demand at low cost. However, costs of transportation, erection, and repair must be reduced before these systems are competitive with current technology. The large size of multi megawatt turbine components makes transportation from manufacturing facilities to wind sites problematic. Once on site, the installation of these machines requires very large and expensive cranes. If a turbine fails during operation, these same cranes must be re-deployed to the site for the repair. This project addresses theses issues through the design of a direct-drive generator/power converter system that uses a modular architecture. Such a design allows for the transport and erection of a multi-megawatt turbine in sub-system-level building blocks. Further, if a module fails during operation, the rest of the turbine can continue producing power while the module is repaired or replaced in situ using on-board service equipment. Phase I developed a conceptual design of a sectional generator and power converter for a 6 MW wind turbine. Assembly procedures and detailed cost estimates were completed. The results showed that an improved cost of energy can be realized with modular, permanent-magnet direct-drive turbines. Phase II will: (1) verify the manufacturing and assembly processes by fabricating a full scale segment of the generator; (2) validate full and partial power mode operation for a 100 kW generator/power converter; and (3) fabricate and test specialized service tools. Commercial Applications and other Benefits as described by the awardee: The technology, which should be ready for commercial development at the multi-megawatt level in Phase III, would be directly applicable to large commercial wind turbines in the fastest growing sector of the energy industry. The result will be a more robust and reliable energy supply to the national grid and a lower cost of energy to the end user.