Magnetic field and coupling effect analysis of a novel dual-rotor dual-stator permanent magnet synchronous generator

Abstract

To tackle the issue of high cost and large volume for offshore wind power generators, a novel dual-rotor dual-stator permanent magnet synchronous generator(DRDS-PMSG)is proposed. The equivalent magnetic circuit model of the generator is established, finite element analysis is performed to evaluate the electromagnetic characteristics and coupling effect, and some simulation results are verified through experiment. The simulation analysis results show that three typical equivalent magnetic circuits exist with changed relative positions between the inner and outer magnets, and the equivalent reluctance of the coupling region can be described using a coupling coefficient. The coupling effect of inner and outer machines is revealed by electromagnetic characteristics, including cogging torque and electromagnetic torque. The peak-to-peak values of the cogging torque of inner and outer machines are 0.52 and 1.64 kN·m, the average values of electromagnetic torque are 11.65 and 27.09 kN·m, and the torque ripples are 6.02% and 4.12%, respectively. In general, a coupling effect exists between the inner and outer machines; however, the coupling effect is effectively reduced by the flux barrier.

Keywords

dual-rotor dual-stator(DRDS) / electromagnetic characteristics / permanent magnet synchronous generator(PMSG) / magnetic field / finite element analysis / coupling effect