Design and Analysis of a Cost-Effective Magnetless Multiphase Flux-Reversal DC-Field Machine for Wind Power Generation

This paper proposes a new four-phase flux-reversal dc-field (FRDC) machine for the wind power generation applications. The key distinction of the proposed generator is to artfully design its stator pole and winding arrangement in a way imitating the permanent-magnet (PM) configurations, which the profound FRPM machine has. Hence, the proposed FRDC generator can provide the bipolar flux-linkage patterns and achieve performances similar to that of the high-quality FRPM generators. The proposed generator can regulate its controllable dc-field winding to vary its flux density effectively. Thus, it can achieve the constant-output-voltage characteristics at different situations in order to extend the battery life and to protect the power grid system. Without installation of any high-cost PM materials, the proposed magnetless FRDC generator can achieve better cost-effectiveness than its PM counterparts. The key performances of the proposed wind power generator are thoughtfully analyzed by the finite-element method, while the experimental prototype is also setup for verifications.