Short flux-paths in switched reluctance generators for direct drive wind energy converters

This paper investigates the design of low speed Switched Reluctance Generators (SRG) based on a different paradigm. The proposed design procedure utilises the formulation of similarity laws and scale models to compare SRG magnetic structures. Besides evaluating regular and similar topologies the scale models are here applied in dimensional analysis of topologies distinguished by different characteristics of electric and magnetic circuits. Furthermore, the scale models methodology can cover physical phenomena like thermal changes and magnetic saturation by introducing some constraints. This work is motivated by the application of SRG to direct drive wind converters and other low speed renewable energy systems. The paper contains the illustration of dimensional analyses on a modular topology with short flux-paths designed for a direct drive wind turbine. Comparing with a regular machine, the short flux-paths topology can optimize the efficiency and weight taking benefits from the significant gain of power per unit of mass and lower losses.