[Show abstract][Hide abstract] ABSTRACT: This paper proposes an optimized rotor pole shape that can effectively reduce the partial demagnetization effect and cogging torque. First, for reducing the peak amplitude of the external field that directly affects the partial demagnetization on the permanent magnets in spoke-type permanent magnet motor, we conduct a variation of core shape and insertion of a barrier. Second, with the rotor shape obtained by the first processes for reducing the partial demagnetization effect, another part of the rotor pole is varied to make better sinusoidal distributed air gap flux density to reduce the cogging torque. In the process of designing the rotor pole shape, a steepest descent method and a response surface method are applied for improving convergence. By using the finite element method, we show that the optimized rotor pole shape drastically reduces the effect of the partial demagnetization and cogging torque.
[Show abstract][Hide abstract] ABSTRACT: This paper proposes the novel flux barrier by using the modified Taguchi method to reduce the cogging torque. In the optimizing process the modified Taguchi method is utilized to consider multiple objective quality characteristics simultaneously such as the torque ripple and the efficiency as well as the cogging torque. The optimal novel flux barrier can effectively reduce the cogging torque and torque ripple and it is verified through the experimental results. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3062959]
[Show abstract][Hide abstract] ABSTRACT: This paper proposes a novel rotor pole shape which consists of a uniform surface and an eccentric surface to make a sinusoidal magnetic flux density in air gap in order to reduce cogging torque, torque ripple, and harmonics of back-electromotive force waveform in spoke-type brushless DC motor. In the process of design and analysis, response surface methodology and the 2-D finite-element method are employed to obtain the rotor geometry and verify the results of the novel rotor pole shape
[Show abstract][Hide abstract] ABSTRACT: This paper proposes the novel flux barrier that built in q-axis in rotor of IPM type BLDC motor. The novel flux barrier aims to reduce the motor vibration with reduced cogging torque and lessened torque ripple by the sinusoidal waveform distribution of the flux generated in the permanent magnet. For optimization of the novel flux barrier, the Taguchi method is effectively employed which considered multiple objective quality characteristics, such as cogging torque, average torque and efficiency. The result of proposed model compare with the initial model and it is verified by 2D finite element method (FEM) results.
Transactions of the Korean Institute of Electrical Engineers 01/2007; 56(3).
[Show abstract][Hide abstract] ABSTRACT: In this paper. design of spoke type BLDC motor which have a characteristics of concentrating fluxes and relatively high reluctance torque among IPM BLDC motors has been researched. To reduce cogging torque and torque ripple. rotor pole shape of optimal design is proposed. To clearly see the effects due to the changed rotor pole shape. magnetic circuit model. 2D FEM and design of experiments (DOE) are used. Then considering these results proper rotor pole shape which have an good effect on air gap flux density and cogging torque. back-emf is designed. Moreover. the validity of proposed model in this paper is also verified by comparison between gained experiment and analysis data.
Transactions of the Korean Institute of Electrical Engineers 01/2007; 56(5).
[Show abstract][Hide abstract] ABSTRACT: This paper proposes a novel designing method of flux barrier in order to reduce cogging torque and torque ripple in the interior permanent magnet type brushless DC motor (IPM type BLDC motor). IPM type BLDC motor is used for high speed and high torque. But IPM type BLDC motor can develop a large cogging torque that may cause noise and vibration. In that sense, this paper suggested that the directions of flux lines generated in the permanent magnet built in the rotor should be sinusoidal waveform distributed within the rotor by such designed flux barriers
[Show abstract][Hide abstract] ABSTRACT: Most single-phase brushless DC (BLDC) motors have unequal air gaps
to eliminate the dead point where the developed torque value is zero.
These unequal air gaps deteriorate the motor characteristics in cogging
torque. Thus in this paper a new topology of the unequal air gaps is
proposed to solve this problem. As a result, it is proved by the finite
element analysis and experimental results that the proposed air gap
topology is very effective in reducing the cogging torque