Magnetic field distribution simulation on two permanent magnet rotor discs with twelve pole pairs

The research development of Axial Flux Permanent Magnet Generator (AFPMG) has been more interesting, as its construction is simple, easy to make (iron coreless), NdFeB type permanent magnet has high density, available everywhere and relatively low price; without using brushes and slip ring, thus the maintenance is not expensive. One of the most influencing components on AFPMG performance is the number of permanent magnet pairs on rotor disc, in which each of them has distance. Distance determines the magnetic flux leakage magnitude that is the magnetic field effect interaction magnitude between magnetic elements. Permanent magnet diameter is 40 mm, distance between magnets, and the number of magnet will determine magnetic orbit, as well as rotor disc radius or AFPMG dimension. This paper discussed magnetic field distribution of each magnetic element on the first rotor disc with each second rotor disc magnetic element. By simulating magnetic field distribution using Finite Element Method Magnetic (FEMM), flux leakage between magnets within one rotor disc can be reduced. Simulation was presented in the geometric form of magnetic field distribution on two permanent magnet elements within one rotor disc toward two magnetic elements on the other rotor disc. The simulation results showed that magnetic field strength in the mid point between magnets in one rotor disc had very small value i.e. 160 mT on the distance of 20 mm.