Abstract:
The effects of permanent magnet material on the performance of PMSM machines is investigated without the use of finite element analysis. A study into magnetic material parameters reveals that the remanent flux and relative recoil permeability of a permanent magnet have the majority of impact on the performance of machines. A rare earth free permanent magnet, MnBiCo, is examined as an alternative material to traditional PMSM magnets. A model for the PMSM is developed paying due diligence to the properties of the magnetic material used in construction of the machine. It is demonstrated that a change in magnetic material will change the torque constant of the motor as well as the inductance of the machine. However, due to most permanent magnet materials having a relative recoil permeability of unity, the change in inductance is negligible. A computer simulation of the PMSM model is developed. A motion control system is simulated. A commercial motor drive is modeled in this simulation. A commercial PMSM is also modeled in this simulation. Performance tests are conducted on the system in both simulation and hardware experiment. The controllers in the computer simulation of the motor drive are modified in order to accurately represent the behavior of the system in the hardware setup. A case study of replacing the ferrite permanent magnets in the specified machine is simulated. MnBiCo magnets produce a motor torque constant 3.95 times larger than that of the ferrite magnets. The performance of the two machines is compared and the results are discussed. It is discovered that the remanent flux of the magnetic material is the sole material property that effects the performance of PMSM machines. The developed simulation will provide motor designers with a quick, simple model for investigating replacement of magnetic material within a PMSM while making no changes to the machine's dimensions or windings.
