A novel stator interior permanent magnet generator for direct-drive wind turbines

Abstract

This is paper presents a novel stator interior permanent magnet generator (SIPMG). A modular stator design is used for the convenience in manufacture and maintenance. The generator has the advantages of rugged rotor and concentrated winding design while the torque ripple is smaller than that produced by a doubly salient machine. Several low-speed multi- pole SIPMGs are designed for direct-drive wind turbines with ratings from 3 MW to 10 MW. Comparisons between SIPMG and rotor-surface-mounted permanent magnet synchronous generator (PMSG) are carried out. It is shown that the SIPMGs have about 130% torque density and 60% cost per kW compared with the PMSG.