Samith Sirimanna with adviser K. Haran
Generators used in wind turbine applications include a variety of topologies depending on the power level and the operating speed. Some of the large-scale wind turbine manufacturers are increasingly interested in direct-drive generators, which improve reliability by eliminating the gear box. Among other candidates, permanent magnet (PM) generators are advantageous in terms of torque density and efficiency.
Recent research by our power and energy group has shown that generator power electronics costs can be significantly reduced by introducing multi-port architecture and controlling only one port using active switches.
However, implementation of this technology requires the synchronous reactance of the generator to be smaller than conventional wind generators.
Our group has previously demonstrated the design of a low inductance, slot-less PM synchronous machine for aerospace applications. The same concept of slot-less machines is adopted here to enable the low- inductance requirement.
As a preliminary step, finite element analysis with Flux 12.1 software was used along with GOSET 2.6 to explore the design space of generator designs as shown in Figure 6. They present the trade-off of generator designs with respect to efficiency and weight for different magnets. This research was supported by ARPA-E.