Multi-objective optimization and analysis of divided-layer varying-network magnetic circuit based axial field flux-switching magnetic gear composite motors

The axial field flux-switching magnetic gear composite machine (AFFSMGCM) is a new type of magnetic field modulation machine with a dual-rotor. Due to the complicated structure of the AFFSMGCM and the nonlinear characteristic of dual magnetic fields coupling, a divided-layer varying-network magnetic circuit (VNMC) method is developed to optimize the machine to obtain a high calculation accuracy and reduce operation time. First, an accurate VNMC model is established according to the magnetic field distribution of an AFFSMGCM. The magnetic field coupling of the rotor and stator permanent magnets (PMs) is performed by the rotary magnetic modulation ring (RMMR). Thus, the magnetic circuit of the RMMR is divided into two layers to reduce the influence of magnetic saturation and leakage flux on the calculation accuracy of the permeances. Then the particle swarm optimization (PSO) method is used to achieve multi-objective optimization of the AFFSMGCM based on the divided-layer VNMC for achieving a large torque, low torque ripple and high efficiency. Next, a multi-physics field coupling analysis is carried out to verify the optimized AFFSMGCM. Finally, a prototype is built and experiments are carried out to validate the AFFSMGCM.