Analytical calculation of air-gap magnetic field distribution and instantaneous characteristics of brushless dc motors

2003 ◽  
Vol 18 (3) ◽  
pp. 424-432 ◽  
Author(s):  
Xinghua Wang ◽  
Qingfu Li ◽  
Shuhong Wang ◽  
Qunfeng Li
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Analytical Calculation ◽  
Air Gap ◽  
Magnetic Field Distribution ◽  
Brushless Dc Motors ◽  
Brushless Dc ◽  
Dc Motors ◽  
Air Gap Magnetic Field

Analytical calculation of magnetic field in surface-mounted permanent-magnet machines with air-gap eccentricity

2019 ◽  
Vol 38 (2) ◽  
pp. 893-914
Author(s):  
Jawad Faiz ◽  
Mohammadreza Hassanzadeh ◽  
Arash Kiyoumarsi
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Field Distribution ◽  
Analytical Calculation ◽  
Air Gap ◽  
Magnetic Field Distribution ◽  
Magnetic Flux Density ◽  
Content Type ◽  
Air Gap Magnetic Field ◽  
The Magnetic Field

Purpose This paper aims to present an analytical method, which combines the complex permeance (CP) and the superposition concept, to predict the air-gap magnetic field distribution in surface-mounted permanent-magnet (SMPM) machines with eccentric air-gap. Design/methodology/approach The superposition concept is used twice; first, to predict the magnetic field distribution in slot-less machine with eccentric air-gap, the machine is divided into a number of sections. Then, for each section, an equivalent air-gap length is determined, and the magnetic field distribution is predicted as a concentric machine model. The air-gap field in the slot-less machine with eccentricity can be combined from these concentric models. Second, the superposition concept is used to find the CP under eccentricity fault. At this end, the original machine is divided into a number of sections which may be different from the one for slot-less magnetic field prediction, and for each section, the CP is obtained by equivalent air-gap length of that section. Finally, the air-gap magnetic field distribution is predicted by multiplying the slot-less magnetic field distribution and the obtained CP. Findings The radial and tangential components of the air-gap magnetic flux density are obtained using the proposed method analytically. The finite element analysis is used to validate the proposed method results, showing good agreements with the analytical results. Originality/value This paper addresses the eccentricity fault impact upon the air-gap magnetic field distribution of SMPM machines. This is done by a combined analysis of the complex permeance (CP) method and the superposition concept. This contrasts to previous studies which have instead focused on the subdomain method.

scholarly journals Magnetic Force Enhancement Using Air-Gap Magnetic Field Manipulation by Optimized Coil Currents

2019 ◽  
Vol 10 (1) ◽  
pp. 104 ◽  
Author(s):  
Jaejoon Lee ◽  
Jaewook Lee
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Magnetic Force ◽  
Air Gap ◽  
Magnetic Field Distribution ◽  
Force Enhancement ◽  
Coil Current ◽  
Design Variables ◽  
Air Gap Magnetic Field ◽  
The Magnetic Field

This paper presents an air-gap magnetic field manipulation by optimized coil currents for a magnetic force enhancement in electromechanical devices. The external coil is designed near the device air-gap for manipulating the magnetic field distribution. The distribution of external coil currents is then optimized for maximizing the magnetic force in the tangential direction to the air-gap line. For the optimization, the design domain near air-gap is divided into small areas, and design variables are assigned at each small design area. The design variables determines not only the strength of coil current density (i.e., number of coil turns) but also whether the material state is coil or iron. In a benchmark actuator example, it is shown that 11.12% force enhancement is available by manipulating the air-gap magnetic field distribution using the optimized coil current. By investigating the magnetic field distribution, it is confirmed that the optimized coil current manipulated the magnetic field, forwarding a focused and inclined distribution that is an ideal distribution for maximizing the magnetic force.

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