Research on a novel combined permanent magnet electrical machine

A novel combined permanent magnet electrical machine has been presented in this paper. The paper describes the design and simulation of a combined electrical machine, in which an outer rotor brushless PM motor is embedded into a novel magnetic gear. A higher torque output for direct drive was transmitted by the combined electrical machine with a topology of inner stator and outer rotor. The numerical-analytical method is applied to calculate the magnetic field. There is no any mesh grid in air gap regions when the magnetic field of a combined electrical machine is computed by the method so that the rotors can be rotated freely. The induced EMF and electromagnetic torque can be conveniently calculated, and the calculated EMF waveform shows good agreement with the measured waveform.