Analysis of Common-mode EMI in PM Synchronous Machines with Fractional-slot Concentrated Winding

The stray capacitances existing between the windings and the frame of the electric machines are the main coupling route of common-mode (CM) electromagnetic interferences (EMI). In this study, the magnitude of parasitic capacitances present in permanent magnet synchronous motor (PMSM) with fractional-slot concentrated winding (FSCW) and conventional-slot distributed winding (DW) are compared through finite element analysis (FEA) simulation. The simulation result shows that a reduced parasitic capacitance and increased CM impedance can be obtained by employing FSCW compared with DW. The Validation of the simulation result is carried out through a practical impedance measurement.