Analytical modeling of split-phase synchronous reluctance machines

Synchronous reluctance (SynRel) motors with rotor flux barriers are gaining increasing attractiveness in automotive applications thanks to their cheap, rugged and magnet-free rotor construction. When equipped with a split-phase stator winding and supplied from multiple inverters, these machines can exhibit further merits as traction motors in regard to enhanced fault tolerance compared to conventional three-phase solutions. Since SynRel motors are usually designed through iterative optimization techniques, it is highly desirable to have accurate and fast methods to predict their performance without the need for time-consuming finite element analysis (FEA) simulations. An analytical procedure is set forth in this paper to analytically model and simulate a SynRel motor with a split-phase stator winding through a magnetic equivalent circuit (MEC) technique. MEC parameters are computed from analytical formulas describing the air-gap magneto-motive force distribution and the magnetic field inside flux barriers. As an output, the air-gap flux density of the SynRel motor can be computed through the presented technique at any operating point. Results are positively assessed by comparison with FEA simulation on a sample SynRel motor including magnetic saturation effects.