Modeling of a Dual Three-Phase Flux-Switching Permanent Magnet Machine Using Two Methods

In this paper, the mathematical model of a dual three-phase flux-switching permanent magnet (FSPM) machine is established and investigated by both methods, namely, the double-dq-frame approach and the vector space decomposition (VSD) theory. Firstly, the dual three-phase PM flux-linkages and stator winding inductances are analyzed via finite element analysis and the major harmonics are considered. Then, an improved transformation based on VSD is proposed to transform the major harmonics into DC components, and shows better decoupled harmonics mapping relationship compared to the double-dq approach. It can also convert the θ-functional inductance matrix to constant form in six dimensions. Finally, the voltage equation and torque equation are derived and compared for both methods. The double-dq approach may be good at interpreting current unbalance, while the VSD approach is more efficient to handle harmonics and results a simple machine model. The work in this paper lays a foundation for the control strategies of the dual three-phase FSPM machine.