Reduction of Cogging Torque of BLDC Motor by Sinusoidal Air-Gap Flux Density Distribution

BLDC 전동기의 정현적 공극 자속밀도 구현에 의한 코깅 토크 저감

  • 김사무엘 (한양대 메카트로닉스공학과) ;
  • 정승호 (한양대 공대 전기전자제어계측공학과) ;
  • 류세현 (전자부품연구원) ;
  • 권병일 (한양대 공대 전자.컴퓨터공학부)
  • Published : 2007.01.01


Along with the development of power electronics and magnetic materials, permanent magnet (PM) brushless direct current (BLDC) motors are now widely used in many fields of modern industry BLDC motors have many advantages such as high efficiency, large peak torque, easy control of speed, and reliable working characteristics. However, Compared with the other electric motors without a PM, BLDC motors with a PM have inherent cogging torque. It is often a principle source of vibration, noise and difficulty of control in BLDC motors. Cogging torque which is produced by the interaction of the rotor magnetic flux and angular variation in the stator magnetic reluctance can be reduced by sinusoidal air-gap flux density waveform due to reduction of variation of magnetic reluctance. Therefore, this paper will present a design method of magnetizing system for reduction of cogging torque and low manufacturing cost of BLDC motor with isotropic bonded neodynium-iron-boron (Nd-Fe-B) magnets in ring type by sinusoidal air-gap flux density distribution. An analytical technique of magnetization makes use of two-dimensional finite element method (2-D FEM) and Preisach model that expresses the hysteresis phenomenon of magnetic materials in order for accurate calculation. In addition, For optimum design of magnetizing fixture, Factorial design which is one of the design of experiments (DOE) is used.


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