Comparison of flux-switching and interior permanent magnet synchronous generators for direct-drivenwind applications based on nelder-mead optimal designing

Abstract

The permanentmagnet flux-switchingmachine (PMFSM) is one of themost promisingmachines withmagnets inserted into the stator. To determine inwhich applications the use of PMFSMis promising, it is essential to compare the PMFSMwithmachines of other types. This study provides a theoretical comparison of the PMFSMwith a conventional interior permanentmagnet synchronousmachine (IPMSM) in the gearless generator of a low-power wind turbine (332 rpm, 51.4 Nm). To provide a fair comparison, both machines are optimized using the Nelder-Mead algorithm. The minimized optimization objectives are the required power of frequency converter, cost of active materials, torque ripple and losses of a generator averaged over the working profile of the wind turbine. In order to reduce the computational time, the substituting profile method is applied. Based on the results of the calculations, the advantages and disadvantages of the considered machines were revealed: the IPMSM has significantly lower losses and higher efficiency than the PMFSM, and the PMFSM requires much less rare-earth magnets and copper and is, therefore, cheaper in mass production. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.