scholarly journals Comparison of Three Analytical Methods for the Precise Calculation of Cogging Torque and Torque Ripple in Axial Flux PM Machines

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ahmed Hemeida ◽  
Bert Hannon ◽  
Hendrik Vansompel ◽  
Peter Sergeant
Keyword(s):  
Permanent Magnet ◽  
Lateral Force ◽  
Torque Ripple ◽  
Analytical Models ◽  
Permanent Magnet Synchronous Machines ◽  
Axial Flux ◽  
Cogging Torque ◽  
Precise Calculation ◽  
Analytical Tools ◽  
2D And 3D

A comparison between different analytical and finite-element (FE) tools for the computation of cogging torque and torque ripple in axial flux permanent-magnet synchronous machines is made. 2D and 3D FE models are the most accurate for the computation of cogging torque and torque ripple. However, they are too time consuming to be used for optimization studies. Therefore, analytical tools are also used to obtain the cogging torque and torque ripple. In this paper, three types of analytical models are considered. They are all based on dividing the machine into many slices in the radial direction. One model computes the lateral force based on the magnetic field distribution in the air gap area. Another model is based on conformal mapping and uses complex Schwarz Christoffel (SC) transformations. The last model is based on the subdomain technique, which divides the studied geometry into a number of separate domains. The different types of models are compared for different slot openings and permanent-magnet widths. One of the main conclusions is that the subdomain model is best suited to compute the cogging torque and torque ripple with a much higher accuracy than the SC model.

scholarly journals Conformal mapping approach for permanent magnet synchronous machines: on the modeling of saturation

2012 ◽  
Vol 61 (2) ◽  
pp. 211-220 ◽  
Author(s):  
Martin Hafner ◽  
David Franck ◽  
Kay Hameyer
Keyword(s):  
Finite Element ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Analytical Models ◽  
Synchronous Machines ◽  
Permanent Magnet Synchronous Machines ◽  
Cogging Torque ◽  
Mapping Approach ◽  
Fe Simulations ◽  
Torque Pulsations

Conformal mapping approach for permanent magnet synchronous machines: on the modeling of saturation In the electromagnetic field simulation of modern servo drives, the computation of higher time and space harmonics is essential to predict torque pulsations, radial forces, ripple torques and cogging torque. Field computation by conformal mapping (CM) techniques is a time-effective method to compute the radial and tangential field components. In the standard CM approach, computational results of cogging torque simulations as well as overload operations observe deviations to nonlinear finite element (FE) simulations due to the neglection of slot leakage and saturation effects. This paper presents an extension of the classical CM. Additional CM parameters are computed from single finite element computations so as to consider both effects listed above in the model over a wide operation range of the electrical drive. The proposed approach is applied to a surface permanent magnet synchronous machine (SM-PMSM), and compared to numerical results obtained by finite element analysis (FEA). An accuracy similar to that of FE simulations is obtained with however the low computation time that is characteristic for analytical models.

Optimization of Magnets Shape for Cogging Torque Reduction in Axial-Flux Permanent Magnet Motors

2021 ◽  
pp. 1-1
Author(s):  
Vicente Simon-Sempere ◽  
Auxiliadora Simon-Gomez ◽  
Manuel Burgos ◽  
Jose-Ramon Cerquides-Bueno
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnet Motors ◽  
Axial Flux ◽  
Cogging Torque

scholarly journals Design and Analysis of a Novel Axial-Radial Flux Permanent Magnet Machine with Halbach-Array Permanent Magnets

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3639
Author(s):  
Rundong Huang ◽  
Chunhua Liu ◽  
Zaixin Song ◽  
Hang Zhao
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Torque Ripple ◽  
Axial Flux ◽  
Element Analysis ◽  
Torque Density ◽  
Axial Forces ◽  
Halbach Array ◽  
Radial Flux ◽  
High Torque

Electric machines with high torque density are needed in many applications, such as electric vehicles, electric robotics, electric ships, electric aircraft, etc. and they can avoid planetary gears thus reducing manufacturing costs. This paper presents a novel axial-radial flux permanent magnet (ARFPM) machine with high torque density. The proposed ARFPM machine integrates both axial-flux and radial-flux machine topologies in a compact space, which effectively improves the copper utilization of the machine. First, the radial rotor can balance the large axial forces on axial rotors and prevent them from deforming due to the forces. On the other hand, the machine adopts Halbach-array permanent magnets (PMs) on the rotors to suppress air-gap flux density harmonics. Also, the Halbach-array PMs can reduce the total attracted force on axial rotors. The operational principle of the ARFPM machine was investigated and analyzed. Then, 3D finite-element analysis (FEA) was conducted to show the merits of the ARFPM machine. Demonstration results with different parameters are compared to obtain an optimal structure. These indicated that the proposed ARFPM machine with Halbach-array PMs can achieve a more sinusoidal back electromotive force (EMF). In addition, a comparative analysis was conducted for the proposed ARFPM machine. The machine was compared with a conventional axial-flux permanent magnet (AFPM) machine and a radial-flux permanent magnet (RFPM) machine based on the same dimensions. This showed that the proposed ARFPM machine had the highest torque density and relatively small torque ripple.

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