Design and Analysis of a Magnetless Flux-Switching DC-Excited Machine for Wind Power Generation

This paper proposes a new outer-rotor magnetless flux-switching DC-excited (FSDC) machine which can offer low-speed operation to directly capture the wind power for power generation. Compared with its permanent-magnet (PM) counterparts, the proposed machine equips no PM such that it enjoys the definite cost benefit. One of the key designs of the proposed machine is the multitoothed per stator pole structure. With the multitoothed structure, the proposed machine not only offers the flux-modulation effect to boost up its torque density, but also is favorable for the low-speed operation. In addition, the external DC-field excitation can be controlled independently to offer the flux-controlled ability to achieve constant voltage output among various wind speeds. By performing the time-stepping finite element method (TS-FEM), the performances of the proposed machine can be analyzed, and hence verifying the design.