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Magnetic circuit

About: Magnetic circuit is a research topic. Over the lifetime, 15707 publications have been published within this topic receiving 118099 citations.


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Journal ArticleDOI
TL;DR: In this paper, the axial hybrid magnetic bearing was designed and assembled for a reaction flywheel system with angular momentum of 15 Nmiddotmmiddots at a speed of 5000 r/min.
Abstract: We propose a new structure for a permanent-magnet-biased axial hybrid magnetic bearing. Starting with the inner air gap and the outer air gap of conventional axial magnetic bearings, we first construct a novel air gap between the permanent magnet and the outer housing, which we call the second air gap, separating the bias flux paths from the control flux paths. As a result, the control flux paths will have lower reluctance, and the power loss of the axial magnetic bearing will be lower. Next, we modeled this axial hybrid magnetic bearing and analyzed it using the equivalent magnetic circuit method, 2-D finite element method (FEM), and 3-D FEM. We have designed and assembled an axial hybrid magnetic bearing prototype for a reaction flywheel system with angular momentum of 15 Nmiddotmmiddots at a speed of 5000 r/min. The theoretical analysis and the prototype experiments show such advantages as simple structure, good force current and force displacement, and high operating reliability.

69 citations

Journal ArticleDOI
TL;DR: In this paper, a novel spoke array PMV machine is proposed to improve working flux density and the torque density of PMV machines, where alternate magnetic bridges are added in the rotor core to connect iron pieces with same polarity and provide magnetic circuit for the low-pole number working magnetic field.
Abstract: In recent years, permanent magnet vernier (PMV) machines are attracting more and more attentions owing to their high torque density feature, which is mainly benefited from its special operation principle called flux modulation effect. Nevertheless, It is found that its working flux density is low, viz., ∼0.3T for modulated flux density in the surface mounted PMV machines. Hence, there is a really large space to further improve the torque density of PMV machine. The spoke array magnet is widely used in the regular PM machine to improve working flux density. However, the flux barrier effect of spoke array magnet for the PMV machine has been proved, and a large torque reduction would be introduced in the high pole ratio spoke array PMV machine. In this paper, a novel spoke array PMV machine is proposed to improve working flux density and the torque density of PMV machines. The alternate magnetic bridges are added in the rotor core to connect iron pieces with same polarity and provide magnetic circuit for the low-pole number working magnetic field, hence the no-load back EMF and output torque of the proposed machine can be significantly improved. Moreover, analytical airgap flux density distribution based on equivalent magnetic circuit is presented to reveal the mechanism of working flux density improvement, and finite element analysis is used to investigate the performance features and structure parameter influence on the key performances, viz., back EMF and torque, of the proposed machine. Finally, a 25 N·m prototype has been built and tested to validate these analyses.

68 citations

Journal ArticleDOI
V. Ostovic1
TL;DR: The ability of the method to evaluate both time and space variations simultaneously is illustrated with graphs which represent the traveling waves in induction machines on a tooth-by-tooth basis.
Abstract: The fundamentals of magnetic equivalent circuit representation of electromechanical systems and the application of these principles to the computation of induction machine dynamics have been previously discussed. Here, some simplifications which clarify the principles of the method and speed up the computation are introduced. The ability of the method to evaluate both time and space variations simultaneously is illustrated with graphs which represent the traveling waves in induction machines on a tooth-by-tooth basis. >

68 citations

Journal ArticleDOI
17 Apr 1990
TL;DR: A thin-film cloth-structured inductor for MAGIC (magnetic integrated circuit) operation in the high-frequency range is described in this paper, where magnetic core arrays with low demagnetizing factor are utilized.
Abstract: A thin-film cloth-structured inductor for MAGIC (magnetic integrated circuit) operation in the high-frequency range is described. To achieve high inductance in a small area, magnetic core arrays with low demagnetizing factor are utilized. To increase the frequency, which is limited by the resonant frequency, the magnetic-strip core arrays are divided into three parts and each core array is excited out of phase; that is, the inductor is composed of three unit inductors connected in series with low mutual coupling. Thus, the resonant frequency of the integrated inductor is high, and high-frequency operation is possible. The experimental inductor is 3*3 mm/sup 2/ in size. The inductance is about 300 nH at 100 MHz, which is about eight times as large as that of the air-core inductor. High inductance can be easily achieved by increasing the number of strip cores with high permeability. >

68 citations

Proceedings ArticleDOI
09 May 1997
TL;DR: In this paper, the design rules for MR fluid actuators in different working modes are presented, and the results of the measurements for various magnetic flux densities are reported and compared.
Abstract: The behavior of actuators based on magnetorheological fluids is determined by a variety of parameters. The magnetorheological properties of the MR suspension, the working mode (shear mode, flow mode, squeeze mode) and the design of the magnetic circuit consisting of MR fluid, flux guide and coil all considerably influence the properties of the actuator. This paper presents design rules for MR fluid actuators in different working modes. The behavior of MR fluids in the three working modes was investigated by using a rotational viscometer, a flow mode damper and a new measuring technique working in the squeeze mode. The measurement results for various magnetic flux densities are reported and the results of the different working modes are compared. High dynamic damping forces dependent on the magnetic field can be achieved especially in the squeeze mode. The design of the magnetic circuit of an MR fluid actuator is analyzed by using finite-element-methods. The advantages of integrating permanent magnets into the magnetic circuit of an MR fluid actuator are pointed out. The working point of the actuator can be adjusted by permanent magnets without consuming any power and the maximum power required to drive the actuator can be reduced. From these results design rules for MR fluid actuators are developed.

68 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202359
2022146
2021286
2020462
2019580
2018555