• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.2
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• pp.55-60
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• 2002

This paper presents an optimization procedure by using Response Surface Methodology(RSM) to determine design parameters for reducing cogging torque. RSM is achieved through using the experimental design method in combination with Finite Element Method and adapted to make analytical model for a complex problem considering a lot of interaction of these parameters. Sequential Quadratic Problem (SQP) method is used to solve the relsulting of constrained nonlinear optimization problem.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.893_894
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• 2009

This paper study on the notch effect for d-q axis inductance of interior type permanent magnet (IPM) motor. The variations of d-q axis inductance are analyzed by finite element method (FEM). Applying the notch for cogging torque minimization and maximization of reluctance torque is confirmed to be improve the torque characteristics. Also, speed characteristics is analyzed according to the load current

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.277-283
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• 2020

In a concentric magnetic gear, which replaces the teeth of a mechanical gear with a permanent magnet, the polar ratio of the magnet that determines the reduction ratio affects the behavior of the magnetic gear dramatically. This study analyzed the density of transmission torque, the efficiency of torque considering the solid loss, and the torque quality, including the cogging characteristics using finite element analysis. When the pole number on the driving side was changed from two to five, it was confirmed that there was an optimal pole ratio, in which the transmission torque was maximized. Because eddy current generation density is proportional to the magnetic field, the transmission efficiency also shows a similar tendency to the transmission torque density, and the efficiency is more than 95% at a low gear ratio. The cogging characteristics due to the interaction of the permanent magnets with the limited number of poles are inversely proportional to the least common multiple between the number of magnets on the drive side and the number of modulator teeth. A test model was built for the transmission torque evaluation.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.92.1-92.1
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• 2008

• Journal of Magnetics
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• v.21 no.4
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• pp.577-585
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• 2016

In this paper, model of the axial-flux permanent magnet synchronous generator (AFPMSG) having arc-shaped trapezoidal permanent magnets (PM) is presented. The proposed model reduces the cogging torque and torque ripple, at the expense of lowering the average output torque. Optimization of the proposed model is performed by considering the asymmetric overhang configuration of the PMs, as to make the output torque of the proposed model competitive with the conventional model. The time stepped 3D finite element analysis (FEA) is performed for the comparative analysis. It is demonstrated that the torque ripple of the optimized model is highly reduced as well as average output torque is increased.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.341-345
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• 2001

Recently, many examples of practical applications of the motors with reluctance torque, such as IPMSM, RM, etc. are reported. However, the problems of the torque ripple produced by the IPMSM, are also presented. The main reasons of the torque ripple generation are the structural imperfectness of the IPMSM and its control system, such as the cogging torque of the motor, the dead time of inverter, sensors offset, imbalance and non-linearity, and so on. In this paper, authors propose a suppression control method of the torque ripple for IPMSM utilizing the repetitive control with the Fourier transformer and a vibration signal detected by an acceleration sensor attached to the motor frame, considering periodicity of the motor torque ripple. An experimental system to simulate the compliant mechanical frame is constructed, and the effectiveness of the proposed method is confirmed by experimental results.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.768_769
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• 2009

Average torque of PMa-SynRM(Permanent Magnet-assisted Synchronous Reluctance Motor) is changed by magnet form inserted to the barrier. Because the magnet form influences to the magnet-torque and reluctance torque. Therefore, this paper present a suitable permanent magnet form design for maximum torque when the magnet quantites are always fixed. And each motor characteristic such as average torque, torque ripple, cogging torque and back-EMF are analyzed by FEM(Finite Element Method) for optimal design..

• Proceedings of the KIEE Conference
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• 1999.11a
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• pp.24-27
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• 1999

This paper proposed a method to reduce torque ripple of double-layer axial flux permanent magnet motor. Torque is generated by interacting between current of stator winding and airgap flux. In the case of slotless axial flux permanent magnet motor, only commutation torque component is significant. Hence, cogging and reluctance torque will not be considered. For this propose, we were supplied differential phase current in each winding and shifted rotor magnet. According to shifted rotor magnet and flux and phase of current were shifted, phase of developed torque in each side is difference. As a result, we could reduce the total torque ripple in motor and obtain minimum torque ripple in the case of 7.5 degree shifting angle between two rotors.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.11
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• pp.28-33
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• 2009

Average torque of PMa-SynRM(Permanent Magnet-assisted Synchronous Reluctance Motor) is changed by magnet form inserted to the barrier. Because the magnet structure inserted to the barrier influences to the magnet-torque and reluctance torque. Therefore, this paper present a suitable permanent magnet form design for maximum torque when the magnet quantites are always fixed. And each motor characteristic such as average torque, torque ripple, cogging torque and back-EMF are analyzed by FEM(Finite Element Method) for optimal design.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1577-1581
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• 2014

This paper presents a method to minimize torque ripple of a V-type IPMSM using the PSO (Particle Swarm Optimization) method with FEM. The proposed algorithm includes one objective function and three design variables for a notch on the surface of a rotor. The simulation model of the V-type IPMSM has 3-phases, 8-poles and 48 slots with 2 notches on the one-pole rotor surface. The arc-angle, length and width of the notch are optimized to minimize the torque ripple of the motor. The cogging torque of the model is reduced by 55.6% and the torque ripple is decreased by 15.5 %. Also, the efficiency of the motor is increased by 15.5 %.