Study of a novel double-stator permanent-magnet electric machine

In addition to the characteristics of conventional motor, the double-stator electric machine system could be operated in the state of generator and motor according to requirement. On the basis of theory analysis and numerical calculation, the output torque is discussed. The influences of the relative position angle of the two stators on the electromagnetic torque are considered. For validating the idea and construction, the authors developed a double-stator prototype motor. The EMF waveforms and output torque waveforms with different magnet arc are discussed when the relative position angle of the two stators varies. The results of Finite Element Method (FEM) Simulation and experiment indicate that the double-stator electric machine is a good scheme for increasing the power density, reducing the torque ripple as a motor and improving the output voltage as a generator.