| Abstract |
Fractional slot permanent magnet synchronous machines with non-overlapping winding (FSPMSM) also known as tooth coil winding permanent synchronous machines (TCW PMSM) have gained intensive attention during the latest decade. Therefore, their design methods are constantly developed and improved. Numerical solution, i.e. finite element analysis (FEA), is still computationally heavy and time consuming, which makes it problematic to use this method in an optimization process. For this reason it is advantageous to use an analytical design method, for searching a design, which satisfies the needed characteristics of a PMSM, during the optimization process. Synchronous inductance is the major parameter of TCW PMSMs, which defines the overload capability of an electrical machine as well as its field weakening characteristics. Armature reaction, together with the permanent magnet flux linkage, specifies the voltage level, which is required for particular operating condition. Therefore, it is important to estimate this parameter as precisely as possible at early design stages. Low armature reaction should be favourable concerning the maximum reachable torque at the nominal speed. However, together with the reduction of the armature reaction, there is decrease of permanent magnet flux linkage, which is undesirable and in order to prevent it, the permanent magnet material amount must be increased.Here, the classical analytical approach of the inductance estimation is used, and a simple alternative to it is presented and evaluated. Also, a lumped model (LM) taking saturation into account has been created. The comparison and verification of the models are done by FEA and by the practical test setup of a 12-slot 10-pole TCW PMSM. |
