A Novel Dual Electrical and Dual Mechanical Wound Field Flux Switching Generator for Co-Rotating and Counter-Rotating Wind Turbine Applications
Wasiq Ullah, Faisal Khan, Udochukwu B. Akuru, Shahid Hussain, Muhammad Yousuf, Siddique Akbar
Abstract
To overcome drastic increase in rare-earth permanent magnet cost, avoid the requirements of brushes, slip rings, and eliminate gear-box mechanism, a novel magnet-less dual electrical and dual mechanical port wound field-excited flux switching generator (DEDMP-WFEFSG) for direct-drive counter rotating wind turbine (D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> CRWT) application is proposed in this paper. The proposed DEDMP-WFEFSG encompasses a stator with dual non-overlapped armature and toroidal field excitation windings; thus, offers reduced overhang and makes the design compact. To ease the design process, lumped parametric magnetic circuit model (LPMCM) for one magnetic pole is formulated. To evaluate the LPMCM design, finite element analysis (FEA) study is undertaken in co-rotation and counter rotation with focus on power distribution between the inner and outer ports. From detailed analysis, it is evident that in comparison with the inner port, the outer port machine offers better average torque, power factor and efficiency. Compared with co-rotation, counter rotation shows improved electromagnetic performance. Finally, to validate the LPMCM and FEA based simulation, a prototype is developed and tested with satisfactory results.