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.

Sensor-less control of a novel axial flux-switching permanent-magnet motor

2018 ◽  
Vol 37 (6) ◽  
pp. 2299-2312
Author(s):  
Javad Rahmani Fard ◽  
Mohammad Ardebili
Keyword(s):  
Kalman Filter ◽  
Permanent Magnet ◽  
Extended Kalman Filter ◽  
Current Sensor ◽  
The Novel ◽  
Permanent Magnet Motor ◽  
Axial Flux ◽  
Content Type ◽  
Stator Current ◽  
Current Sensors

Purpose The purpose of this paper is to suggest a novel current sensor-less drive system for a novel axial flux-switching permanent-magnet motor drive to reduce the costs and avoid problems caused by faults of the current sensors. Design/methodology/approach Commonly, a conventional controller needs at least two current sensors; in this paper, the current sensors are removed by replacing estimated stator current with the extended Kalman filter. Findings A prototype of the novel axial flux-switching permanent-magnet motor is fabricated and tested. It is found that the experimental results confirm the proposed method and show that the control has almost the same performance and ability as the conventional control. Originality/value The axial flux-switching permanent-magnet motor is one of the most efficient motors, but current sensor-less control of an axial flux-switching permanent-magnet motor with a sandwiched permanent magnet and a unity displacement winding factor has not been specially reported to date. Thus, in this paper, the authors report on current sensor-less control based on the extended Kalman filter for electric vehicles.

An Optimal Method for Minimizing Cogging Torque in Disc-Type Permanent Magnet Machines Using FEM and Genetic Algorithm

2013 ◽  
Vol 416-417 ◽  
pp. 21-26
Author(s):  
Jing Shi Shangguan ◽  
Cheng Zhi Fan
Keyword(s):  
Genetic Algorithm ◽  
Permanent Magnet ◽  
Permanent Magnet Machines ◽  
Optimal Method ◽  
Cogging Torque ◽  
Slot Opening ◽  
The Impact

Cogging torque is one of the main reasons which cause ripple in motor's speed and torque. So the reduction of cogging torque must be considered in the design of permanent magnet machines. There are many existing techniques for reducing cogging torque in PM machines. This paper presents a new optimal method for cogging torque minimization by magnet shifting in disc-type PM machines. The impact of magnet shifting on cogging torque and torque output are discussed in disc-type PM machines. In order to reduce the cogging torque effectively while without being harmful to the average torque output. This paper used genetic algorithm (GA) to calculate the shift positions combined with slot-opening optimization to achieve the minimum cogging torque.

The impact of the self-sealing coolant channel across the stator core on the electromagnetic performance of the permanent magnet motor

2022 ◽  
pp. 1-23
Author(s):  
Tian Xia ◽  
Falong Zhu ◽  
Peng Kang ◽  
Buyun Sheng ◽  
Yiming Qiu
Keyword(s):  
Permanent Magnet ◽  
Temperature Rise ◽  
Heat Dissipation ◽  
Design Method ◽  
Permanent Magnet Synchronous Motor ◽  
Core Loss ◽  
Synchronous Motor ◽  
Permanent Magnet Motor ◽  
Stator Core ◽  
The Impact

For avoiding the damage of the insulation and permanent magnet, the temperature rise of the PMSM (permanent magnet synchronous motor) should be controlled strictly, it is usually one of the main objectives during improving the output power and torque density beyond the state-of-the-art in motor design. In this research, the coolant channel will be placed within the yoke of the stator core to enhance the heat transfer between the stator core and the coolant. Hydrophobic coating is applied to replace the metal tube for increasing the utilization of the cross area of the coolant channel. The impact of the coolant channel on the performance of the permanent magnet motor is analyzed. A general design method of the coolant channel is presented. The result shows that the change of the stator core loss is within about 10% as the coolant channel is moved away from the slot along the radial direction while the back electromotive force of the motor could keep constant through appropriate design. The impacts of the coolant channels on the magnet performance and the heat dissipation performance could be divided completely with the design method. The method can be applied on various PMSM including SPM (surface-mounted permanent magnet motor) and IPMSM (interior permanent magnet synchronous motor). Sufficient coolant flow could be provide to help conduct the temperature rise of the motor.

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.

Permanent magnet shaping for cogging torque and torque ripple reduction of PMSM

2018 ◽  
Vol 37 (6) ◽  
pp. 2232-2248
Author(s):  
Brahim Ladghem Chikouche ◽  
Kamel Boughrara ◽  
Rachid Ibtiouen
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
Opening Angle ◽  
Cogging Torque ◽  
Content Type ◽  
Torque Ripple Reduction ◽  
Ripple Reduction ◽  
Slot Opening ◽  
A New Technique ◽  
Torque Ripples

Purpose This paper aims to the improvement of permanent magnet shape in the popular permanent magnet synchronous machine (PMSM) is proposed in this paper in view to mitigate cogging torque magnitude and torque ripple. Design/methodology/approach A two-dimensional exact analytical approach of magnetic field distribution is established for the PMSM considering magnet shape and slot opening. The optimal magnet shape is constituted of small number of layers stacked radially. The thickness of each magnet layer is considered equal to about one mm or more; however, a parametric study was performed to determine pole pitch ratio value. The finite element method is used to validate the analytical results. Findings Cogging torque peaks and torque ripples can be mitigated significantly more than 90 per cent compared to results issued from machine having classical magnet shape. Raising the number of magnet layers can give better results. The results of this paper are compared also with those issued from the machine having sinusoidal magnet shape and give a good solution. Originality/value A new technique for cogging torque and torque ripple mitigation is proposed in this paper by changing permanent magnet shape. The proposed final magnet shape is constituted of a set of stacked and well-dimensioned layers relative to the opening angle.

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