Design on notch structure of stator tooth to reduce of cogging torque of single-phase BLDC motor
This paper proposes the design method on the notch structure of stator tooth to reduce the cogging torque of the single-phase brushless Direct Current (BLDC) Motor. The single phase BLDC motors generates the dead-point causing a starting failure. This problem is solved by using an asymmetric air-gap structure. However, the asymmetric air-gap structure increases the cogging torque causing a noise and vibration of BLDC motor. Therefore, the reduction of cogging torque is essential to improve the performance of BLDC motor. This study for reducing the cogging torque of BLDC motors applies to notch structure of stator because of ease of application and low cost. In this paper, Availability on reduction of cogging torque of the asymmetric notch is proved by using two-notches. Then, the reduction of cogging torque is proved by using the finite element analysis(FEA).
Axially Stacked Multiphase Flux Reversal Machine
This paper introduces a novel three-phase flux reversal machine. Unlike conventional machines, the proposed machine is based on a multi-layered design with three magnetically independent rotors and stators on the same shaft. Each layer represents a single-phase flux reversal machine (FRM), which is mechanically shifted against each other. Each layer consists of a stator with two teeth, where two magnets of opposite polarity are radially attached to each tooth. The salient rotor consists of three poles, which are located 120° apart. This multilayered structure compensates for shortcomings of the single-phase FRM like high torque pulsations and vanishing starting torque at specific rotor positions. These advantages of the three-phase machine will be supported through various analyses, comparisons and simulations presented in this paper.
Studies of Regression in a Transplantable Tumor in Mice *
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