10MW, 10rpm, 30Hz spoke Ferrite and bonded NdFeB-rotor wind PMSG preliminary design with FEM validations for 6 rotor variants

Abstract

In an effort to increase the efficiency close to 0.97 for a power factor above 0.7, at maximum 70 tons (250,000USD) active weight (and cost) for 10 MW, 10rpm wind generator, a Ferrite spoke-PM and bonded NdFeB respectively, multi pole rotor, 3 phase radial air gap synchronous generator was designed here, with key FEM validation checks regarding the flux density distribution and torque waveform and Ldm, Lqm inductances for pure Iq field-oriented control (FOC). The rotor was provided with flux barriers in axis q, to further reduce q axis inductance and thus increase power factor. Two variants of rotor core geometry have been considered: one with a single lamination (without and with additional radial magnets) and one with detachable poles with flux barriers; in all, 6 rotor variants. It has been also proved that the generator can survive approx. 2.00 p.u. load without serious PM demagnetization.