Design and analysis of a high-performance surface inset permanent magnet motor with asymmetrical rotor

2020 ◽  
Vol 64 (1-4) ◽  
pp. 211-220
Author(s):  
Wenliang Zhao ◽  
Cong Liu ◽  
Yujing Li ◽  
Xue Fan ◽  
Xiuhe Wang

This paper presents a novel design strategy for surface inset permanent magnet (SIPM) motors to suppress torque pulsations and maintain the high output torque by integrating the magnet skewing and asymmetrical rotor configurations. The magnet skewing is implemented within one magnet pole pitch to reduce cogging torque by avoiding excessive torque degradation, and the asymmetrical rotor is designed to improve the utilization of the torque components, thus to compensate the decreased torque due to the magnet skewing. To highlight the advantages of the proposed motor, a conventional SIPM motor is adopted for performance comparison with the aid of the finite element method. As a result, the proposed SIPM motor highly reduced the cogging torque (−79.7%) and torque ripple (−54.7%) while maintaining a high average torque when compared to the conventional SIPM motor.

2011 ◽  
Vol 383-390 ◽  
pp. 6156-6161 ◽  
Author(s):  
Chang Chou Hwang ◽  
Chia Ming Chang ◽  
Ping Huey Tang

This paper presents a 3-phase, 7 kW, 3900 rpm, 4-pole, 12-slot interior permanent magnet (IPM) synchronous motor for machine tool applications. To reduce the torque pulsations of the initial designed motor, three small circular holes are drilled in the magnetic island, and the Taguchi parameter method coupled with the finite element method (FEM) analysis is employed to minimize the level of cogging torque, torque ripple and magnet volume of the motor. Results from the optimized motor demonstrate that the motor is favorable regarding cogging torque minimization, torque ripple minimization and magnet volume minimization


2020 ◽  
Vol 64 (1-4) ◽  
pp. 79-89
Author(s):  
Yan Liu ◽  
Wenliang Zhao ◽  
Xue Fan ◽  
Xiuhe Wang ◽  
Byung-il Kwon

This paper proposes an optimal design for a surface-mounted permanent magnet motor (SPMM) to reduce torque pulsations, including cogging torque and torque ripple, by using multi-grade ferrite magnets. Based on a conventional SPMM with single-grade ferrite magnets, the proposed SPMM is designed with four-grade ferrite magnets and then optimized to minimize torque pulsations by maintaining the required torque, utilizing the Kriging method and a genetic algorithm. The results obtained by the finite element analysis show that the optimized SPMM with multi-grade ferrite magnets exhibits improved airgap flux density distribution with highly reduced cogging torque and torque ripple by maintaining the same average torque, as compared to the conventional SPMM. Furthermore, the analysis of the working points for the multi-grade ferrite magnets reveals that the optimized SPMM has good durability against the irreversible demagnetization.


2012 ◽  
Vol 433-440 ◽  
pp. 4201-4206
Author(s):  
Yue Jun An ◽  
Wen Qiang Zhao ◽  
Li Ping Xue ◽  
Hong Liang Wen ◽  
Guo Ming Liu

Cogging torque is one of the most important parameters of permanent magnet motors, which causes torque ripple, vibration and noise. This paper describes the mechanism of cogging torque, introduces several methods of reducing cogging torque and points out the advantage of novel magnet arrayed permanent magnet motor in reducing cogging torque. Ansoft software is used to build the simulation of conventional surface-type permanent magnet motor and novel magnet arrayed permanent magnet motor and to calculate their cogging torque. a cogging torque testing system which included the angle sensor, permanent magnet motor, torque wrenches and other components are tested two different structures motors’ cogging torque .The experimental result is consistent with the simulation results, it shows that the method of novel magnet arrayed permanent magnet motor reducing cogging torque is correct. The new method compare with the same specification on the surface of permanent magnet motor can reduce more cogging torque.


2011 ◽  
Vol 383-390 ◽  
pp. 1369-1375
Author(s):  
Yue Jun An ◽  
Wen Qiang Zhao ◽  
Li Ping Xue ◽  
Hong Liang Wen ◽  
Guo Ming Liu

Cogging torque is one of the most important parameters of permanent magnet motors, which causes torque ripple, vibration and noise. This paper describes the mechanism of cogging torque, introduces several methods of reducing cogging torque and points out the advantage of novel magnet arrayed permanent magnet motor in reducing cogging torque. Ansoft software is used to build the simulation of conventional surface-type permanent magnet motor and novel magnet arrayed permanent magnet motor and to calculate their cogging torque. a cogging torque testing system which included the angle sensor, permanent magnet motor, torque wrenches and other components are tested two different structures motors’ cogging torque .The experimental result is consistent with the simulation results, it shows that the method of novel magnet arrayed permanent magnet motor reducing cogging torque is correct. The new method compare with the same specification on the surface of permanent magnet motor can reduce more cogging torque.


Author(s):  
Ravisankar B Et.al

Permanent magnet (PM) motors are rapidly replacing the squirrel cage induction motors for its energy efficient operation, smooth control and high power density. Although PM Motors are energy efficient, they are inherently affected by cogging torque and torque ripple. Magnetic alignment between teeth of stator and permanent magnet of rotors produce cogging torque. Torque ripple is a dynamic oscillation during steady-steady operation which leads to various mechanical anomalies like vibration, noise and rotor stress. Torque ripple is produced in PM motors because of non-sinusoidal distribution of flux, saturation, improper selection of slots etc., these ill effects will deteriorate the starting and steady-state performance of motors. So it is very vital to make analysis and prediction of cogging torque and torque ripples to make the motor more effective. Now a day's minimizing the torque ripples and cogging torque are gaining importance in PM motor designs. In this proposed work, the cogging torque analysis and torque ripple analysis of permanent magnet motor and line start permanent magnet motor has been done and reported.


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