The Structure of Symmetrical Stator Core Offset to Reduce Cogging Torque

2021 ◽  
Author(s):  
Tao Zhou ◽  
Li Zhu
Keyword(s):  
Stator Core ◽  
Cogging Torque

scholarly journals A Design Method for the Cogging Torque Minimization of Permanent Magnet Machines with a Segmented Stator Core Based on ANN Surrogate Models

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1880
Author(s):  
Elia Brescia ◽  
Donatello Costantino ◽  
Paolo Roberto Massenio ◽  
Vito Giuseppe Monopoli ◽  
Francesco Cupertino ◽  
...  
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
Design Method ◽  
Heuristic Approach ◽  
Topological Optimization ◽  
Permanent Magnet Machines ◽  
Stator Core ◽  
Cogging Torque ◽  
Design Formula ◽  
Harmonic Components

Permanent magnet machines with segmented stator cores are affected by additional harmonic components of the cogging torque which cannot be minimized by conventional methods adopted for one-piece stator machines. In this study, a novel approach is proposed to minimize the cogging torque of such machines. This approach is based on the design of multiple independent shapes of the tooth tips through a topological optimization. Theoretical studies define a design formula that allows to choose the number of independent shapes to be designed, based on the number of stator core segments. Moreover, a computationally-efficient heuristic approach based on genetic algorithms and artificial neural network-based surrogate models solves the topological optimization and finds the optimal tooth tips shapes. Simulation studies with the finite element method validates the design formula and the effectiveness of the proposed method in suppressing the additional harmonic components. Moreover, a comparison with a conventional heuristic approach based on a genetic algorithm directly coupled to finite element analysis assesses the superiority of the proposed approach. Finally, a sensitivity analysis on assembling and manufacturing tolerances proves the robustness of the proposed design method.

Cogging torque due to roundness errors of the inner stator core surface

2003 ◽  
Vol 39 (3) ◽  
pp. 1622-1625 ◽  
Author(s):  
M. Kitamura ◽  
Y. Enomoto ◽  
J. Kaneda ◽  
M. Komuro
Keyword(s):  
Stator Core ◽  
Cogging Torque ◽  
Core Surface

scholarly journals Analysis of the stator topology impact on cogging torque for surface permanent magnet motor

2015 ◽  
Vol 34 (2) ◽  
pp. 456-474 ◽  
Author(s):  
Lidija Petkovska ◽  
Goga Cvetkovski ◽  
Paul Lefley
Keyword(s):  
Permanent Magnet ◽  
Generic Model ◽  
The Novel ◽  
Permanent Magnet Motor ◽  
Stator Core ◽  
Cogging Torque ◽  
Content Type ◽  
Slot Opening ◽  
The Impact ◽  
Static Torque

Purpose – The purpose of this paper is to investigate the impact of the stator core design for a surface permanent magnet motor (SPMM) on the cogging torque profile. The objective is to show how the cogging torque of this type of motor can be significantly reduced by implementing an original compound technique by skewing stator slots and inserting wedges in the slot openings. Design/methodology/approach – At the beginning generic model of a SPMM is studied. By using FEA, for this idealised assembly, characteristics of cogging and electromagnetic torque are simulated and determined for one period of their change. Afterwards, actual stator design of the original SPMM is described. It is thoroughly investigated and the torque characteristics are compared with the generic ones. While the static torque is slightly decreased, the peak cogging torque is almost doubled and the curve exhibits an uneven profile. The first method for cogging torque reduction is skewing the stator stack. The second technique is to insert wedges of SMC in the slot openings. By using 2D and 2 1/2D numerical experiment cogging curves are calculated and compared. The best results are achieved by combining the two techniques. The comparative analyses of the motor models show the advantages of the proposed novel stator topology. Findings – It is presented how the peak cogging torque can be substantially decreased due to changes in the stator topology. The constraint is to keep the same stator lamination. By skewing stator stack for one slot pitch 10° the peak cogging torque is threefold reduced. The SMC wedges in slot opening decrease the peak cogging almost four times. The novel stator topology, a combination of the former ones, leads to peak cogging of respectable 0.182 Nm, which is reduced for 7.45 times. Originality/value – The paper presents an original compound technique for cogging torque reduction, by combining the stator stack skewing and inserting SMC wedges in the slot openings.

Cogging torque in SPM machine with segmented stator

2016 ◽  
Vol 35 (2) ◽  
pp. 641-654 ◽  
Author(s):  
Jian-Xin Shen ◽  
Shun Cai ◽  
Jian Yuan ◽  
Shuai Cao ◽  
Cen-Wei Shi
Keyword(s):  
Design Methodology ◽  
Optimal Solution ◽  
Analytical Prediction ◽  
Stator Core ◽  
Cogging Torque ◽  
Content Type ◽  
Air Gaps ◽  
Different Shapes ◽  
Number Of Segments ◽  
Practical Implications

Purpose – The purpose of this paper is to evaluate the cogging torque in a surface-mounted permanent magnet (SPM) machine with both uniformly and non-uniformly segmented stator cores and to find out the optimal solution of stator core segmenting. Design/methodology/approach – The cogging torque with segmented stators is synthesized from a single slot model, and analytical prediction is given to analyze the cogging torque with both uniformly and non-uniformly segmented stators. Finite element method (FEM) is used to figure out the electromagnetic field and validate the analytical prediction. Moreover, models with various shapes and positions of connecting tongues between the stator core segments are explored to achieve the optimal design. Findings – The cogging torque is found to be greatly related to the number of segments and the electrical angle between adjacent additional air gaps caused by the tolerance of stator segments. Different shapes of the connecting tongues are tested and proved to be of great importance to the flux density, both radial and tangential, and therefore affect the cogging torque. Finally, position of the connecting tongues is perceived to have little influence on the performance of machine. Practical/implications – By utilizing analytical prediction and FEM calculation, the optimal solution is discussed to minimize the cogging torque in the SPM machine from the perspective of the stator core segmentation. Originality/value – This paper establishes formula of cogging torque with segmented stators and predicts the variation of cogging torque with analytical method. Besides, different combinations of segments are compared and measures to reduce the cogging torque produced by the segmentation are proposed.

scholarly journals Stator flux barriers to improving interior permanent magnet motor characteristics

2021 ◽  
Vol 927 (1) ◽  
pp. 012040
Author(s):  
P Irasari ◽  
P Widiyanto
Keyword(s):  
Permanent Magnet ◽  
Core Loss ◽  
Permanent Magnet Motor ◽  
Stator Core ◽  
Element Analysis ◽  
Cogging Torque ◽  
Output Torque ◽  
Interior Permanent Magnet ◽  
Stator Flux ◽  
Interior Permanent Magnet Motor

Abstract There are many methods to improve the characteristics of permanent magnet motors. One of them is by making flux barriers on the stator or rotor, or both. This paper discusses the adding stator flux barriers on the rectangular-shaped stator of the interior permanent magnet motor. The purpose is to increase the maximum rotation of the machine. The shape of the flux barrier is circular considering the ease of the manufacturing process, with the proposed diameter is one slot pitch. Several diameters of larger and smaller sizes will also be simulated for comparison. Other parameters, which are cogging torque and stator core loss, are also investigated. Design and simulation are carried out analytically and numerically using 2D finite element analysis. The simulation results indicate that the proposed flux barrier diameter can provide the maximum rotation with only a tiny decrease in output torque. In this regard, it can be concluded that the stator flux barriers affect the speed than output torque. Additional advantages are also obtained from the decrease in cogging torque and core loss at the base speed compared to a stator without flux barriers.

Sign in / Sign up

Export Citation Format

Share Document