High Torque Density Double Stator PM Synchronous Machine

High torque density and high efficiency are two important factors in electrified automotive and aerospace applications. These attributes have been achieved here by optimizing motional forces within the rotor of a Double Stator Permanent Magnet (DSPM) synchronous machine. In this paper, a 96-kW high torque density (206.7Nm/L and 28.2Nm/kg including end windings) electric machine is introduced along with cooling mechanism and accompanying drive system. This machine houses two stators with concentrated windings and tangentially magnetized permanent magnet segments on the rotor. The stator uses an E-core arrangement to eliminate the mutual inductance, similar to spoke type machines, thereby increasing the torque density. To prevent local demagnetization on the corners of permanent magnets, the shape of permanent magnets and rotor segments have been modified. Moreover, 3D Finite Element Analysis (FEA) is carried out to investigate the effect of end windings on motor performance including torque speed curve and torque and power density at a base speed of 1500 rpm.