For special types of electric machines, it is essential and of utmost interest to develop mathematical model and characterize the machine for performance evaluation and testing the machine for study and applications. A two-dimensional analytical method for the performance evaluation of axial flux permanent magnet (AFPM) machine has been presented in this paper. The method computes the electromagnetic torque, magnetic field distribution, cogging torque and back EMF of the machine using quasi-3D modeling. Fourier Transform is used for the solution of Maxwell's equations in different regions of the AFPM machine. A surface mounted AFPM motor is designed and developed in workshop and tested. Experimental results are demonstrated and compared with the results computed from analytical model to validate the effectiveness and accuracy of the proposed method.

Analysis and determination of magnetic field distribution of surface mounted permanent magnet (SMPM) motors has always been a topic of research. Though a number of methods like two‐dimensional numerical and analytical methods have been proposed to evaluate the magnetic field and parameters of radial flux SMPM motors, the methods developed for axial flux permanent magnet motors are mainly three dimensional. Numerical methods provide accurate results but are not suitable for initial design analysis. The analytical methods are known for their accuracy, convenience, as well as are less time consuming than numerical methods. The analytical methods like conventional design method, magnetic equivalent circuit, generalised machine theory and Fourier analysis present in the literature for SMPM motor have been investigated in this study and the results obtained are compared and evaluated for radial flux SMPM and axial flux SMPM. Experimental results are included to demonstrate the percentage error obtained from different methods and denote the accuracy. From the comparison of different results, it can be concluded that the Fourier transform method is more realistic approach and is capable of computing the performance as well as field distribution simultaneously.

The paper presents an analytical model for determining performance characteristics of surface mounted permanent magnet brushless motor using Fourier transform technique. The proposed scheme assumes a simplified geometric model of surface mounted PM (SMPM) motor with dual current sheets using layer theory to analyse electrical machines. The layer theory considers regions of PMBLAC motor to be replaced by layers of respective homogeneous material properties. Isotropic model assumes stator to be sloltless while anisotropic model is also considered to account for stator slotting effect on the motor performance. The Fourier transform applicable to linear induction motor and introduced by S. Yamamura is modified and adapted for analysing PMBLAC motor. The primary stator winding and permanent magnets on rotor are replaced by their respective equivalent linear current densities. The proposed model is validated using experimental results from a 12‐slot surface mounted PMBLAC motor. The proposed method is capable of calculating the effect of design parameters on the performance of the SMPM motor, thus making it suitable for design and optimisation at initial stage. Moreover, analytical validation is also presented to prove the effectiveness of the proposed method.

The search for replacement of commutator and brushes in conventional DC motors by electronic commutator has resulted in a class of Permanent Magnet Brush Less (PMBL) motors. The operation of PMBL motor requires synchronization of coil currents with the instantaneous rotor position. The applied voltages of higher magnitudes must have same zero crossings as that of speed induced back EMF of the respective stator windings. The complexity of rotor position detection in PMBL motor is overcome by obtaining a replica of stator induced EMF using additional auxiliary stator and rotor. The auxiliary stator winding induced EMF is amplified using Power Operational Amplifier (P-OPAMP) and the output is connected to the main stator winding. The proposed scheme has been tested at laboratory scale and has been found to be a promising alternative scheme for operation of PMBLDC/AC motors.

A two-dimensional analytical method for the performance evaluation of axial flux permanent magnet (AFPM) machine has been presented in this paper. The method computes the electromagnetic torque, magnetic field distribution, cogging torque and back EMF of the machine using quasi-3D modeling. Fourier Transform is used for the solution of Maxwell's equations in different regions of the AFPM machine. A surface mounted AFPM motor is tested and the experimental results validate the proposed method.