Investigation of Maximum Torque of Interior Permanent Magnet Type Magnetic-Geared Generator Based on Magnetic Interaction

Magnetic-geared generators (MGGs) are expected to be applied to wind-power generation because of high torque density and efficiency. Among them, an interior permanent magnet (IPM)-type MGG shows different characteristics compared to a surface permanent magnet (SPM)-type MGG. The reason is that since its high-speed rotor (HSR) does not have the iron yoke, the magnetic flux from the stator coil gets through and modulated by pole-pieces (PPs). Eventually, the modulated flux reaches the low-speed rotor (LSR). Since the stall torque of the magnetic gear is determined by the modulated flux, the stall torque of the IPM-type MMG would be influenced by the magnetic flux generated by the stator coil. This phenomenon is called magnetic interaction. This paper investigated the change of the maximum torque of the IPM-type MMG based on the of magnetic interaction by using both a three-dimensional finite element method (3D-FEM) and experiment.