Anubhav Bose with Advisor K. Haran

Integrated Generator-Rectifier Systems have been shown to improve reliability and operating efficiency of offshore wind turbine generation systems, as well as reduce the overall Levelized Cost of Energy (LCoE) and Annual Energy Production (AEP) from these systems.  These advantages have been shown in design studies at the 10 MW scale, as well as in laboratory testing at the 200-kW scale.  For long term system level demonstration of this architectur e, a 20-kW scale wind turbine system is being deployed near the University of Illinois Urbana-Champaign campus.  This research focuses on the design & development of the slotless permanent magnet multi-port generator that enables this architecture.

The generator is designed with a Multiphysics view in mind, considering not just the electromagnetics, but also the thermal, environmental and mechanical aspects.  An analytical sizing framework is being developed for determining preliminary performance during the conceptual design stage.  Finite Element based optimization routines are used to refine the performance characteristics of baseline design, and also to assess the impacts of different design choices such as torque ratings, port count and other geometric considerations.  Thermal and mechanical analysis is performed to ensure the robustness of the generator when operating at its rated load inside a wind turbine nacelle environment.

Initial results indicate that even at this low power scale, significant benefits in weight, efficiency and thermal performance can be obtained by the optimized designs over the current baseline.  Future work involves system level verification and manufacturing of the generator, followed by reliability checks and test runs at the PRDC dyno.  Once the system operation has been validated, the system will replace the baseline generator and power electronics on the wind turbine system on campus and run for over a year to verify the LCoE and AEP improvements.

Figure 24. Top: CAD rendering of the proposed Generator Design; Bottom: Winding Layout Diagram of the multi-port generator.

Figure 25. Top: The Design Space for the 20 kW Generator Design; Bottom: Selected Results from the FEA-based Optimization.