Mini review on the design of axial type eddy current braking technology
01 Dec 2019-International Journal of Power Electronics and Drive Systems (Institute of Advanced Engineering and Science)-Vol. 10, Iss: 4, pp 2198-2205
TL;DR: In this paper, a solid review of the design of axial eddy current braking system is presented, which is very promising for an alternative braking system for electric vehicles, and a potential issue for developing axial ECB is also discussed to explore the braking performance improvement of the axial type.
Abstract: Eddy Current Brake (ECB) is a type of electric braking that uses eddy current to produce braking forces. This article delivers a solid review of the design of Axial ECB, which is very promising for an alternative braking system. Several types of axial ECB are classified and named as a single disk, double disk, and unipolar model. The classification of axial ECB is based on the design of coil placement, which induces axial area of the disk as well as the electromagnet source. A potential issue for the development of axial ECB is also discussed to explore the braking performance improvement of the axial type ECB. It was highlighted that research on how to change the direction of magnetic field vectors by changing the shape of the pole-shoe on the electromagnetic ECB in axial type has not been widely studied. Therefore, this issue would be interesting for future investigation.
Citations
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TL;DR: In this paper, a compact eddy current brake (ECB) is obtained by distributing the required braking torque from the disc brake into multiple electromagnets, and the results show that the developed compact ECB could produce 93.66% of the torque required for braking.
Abstract: The braking system in a vehicle has the main role of slowing down the speed or stopping the moving vehicle. Compared to mechanical braking, which utilizes friction, non-contact braking has several advantages, including longer lifetime and less maintenance. One form of non-contact braking systems is the eddy current brake (ECB), an electric braking system that employs eddy currents to operate. This research focuses on the impact of magnetic field sources used in the ECB. In addition, the number of magnetic field sources is also observed. In order to achieve an ECB design that can be easily applied in any types of vehicles, including motorcycles and compact cars, a compact ECB design with an excellent braking torque is required. In this study, a compact design of the ECB is obtained by distributing the required braking torque from the disc brake into multiple electromagnets. Finite element method-based modeling has been performed to study ECB parameters, including the number of coil winding, the number of electromagnets, and the electric current. The results of this study show that the developed compact ECB could produce 93.66% of the torque required for braking.
13 citations
01 Nov 2019
TL;DR: This paper aims to know the influence between the shapes of conductor’s face on braking torque using finite element method, using aluminum with mid-iron in one construction to improve the braking torque produced by conductor.
Abstract: Vehicles are the most important thing to use by human and to make it safe to use, all vehicle need a safe and reliable braking system, the use of frictional brake can raise the probability of braking failure because of high pressure and temperature operation, to make braking safer, there is a new, alternative braking system called Eddy-Current Brake (ECB) that uses magnet in their braking process. This paper aims to know the influence between the shapes of conductor’s face on braking torque using finite element method, using aluminum with mid-iron in one construction to improve the braking torque produced by conductor. Validation was done before starting FEM calculation to achieve accurate FEM settings, the modeling uses ANSYS Electronics Desktop. The shapes used on conductor’s face are sawtooth, half-circle, and square. The highest braking torque performance on these variables are 15.39213, 16.40432, and 14.25 Nm respectively at their critical speed with a magnetic flux of 0.8 – 2 Tesla at all variables.
10 citations
Cites methods from "Mini review on the design of axial ..."
...shows the construction of FEM of grooved conductor, using unipolar type electromagnet that has been used before [13], the electromagnet specifications are 20 A, 12 v, and 360 coil winding....
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Proceedings Article•
02 Sep 2004
TL;DR: In this paper, the authors proposed a squirrel cage-type coupling disk, which forces eddy currents to flow perpendicular to both magnetic field lines and the axis of rotation to optimize the Lorentz force and transmitted torque.
Abstract: Eddy-current couplings are becoming popular devices for speed and torque control. Efficiency of these couplings depends on the excitation level; therefore, the routes and density of induced currents affect it significantly. This paper focuses on the design of a squirrel cage-type coupling disk, which forces eddy currents to flow perpendicular to both magnetic field lines and the axis of rotation. Lorentz force and transmitted torque are consequently optimized. The investigation is performed both numerically and experimentally, with results being presented for variable air gaps and speeds. A comparison between plain and slotted disk conductors, tested under identical set-ups, demonstrates the effect of the proposed design on torque throughput and efficiency. In addition to this, the influence of number and size of slots and the effect of filling slots with iron are studied by parametric finite-element modeling verified by experiments.
10 citations
TL;DR: In this article, the authors presented a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects.
Abstract: The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analytical and 3D modelling, the amount of braking torque at a low speed was found to have an average error for the equation using a correction factor of 1.78 Nm, while after repairing, a value of 1.16 Nm was obtained. For the overall speed, an average error of 14.63 Nm was achieved, while the proposed equation had a small difference of 1.79 Nm. The torque difference from the calculation results of the proposed model with the measurement value in the experiment was 4.9%. Therefore, it can be concluded that the proposed equation provided a better braking torque value approach for both low and high speeds.
7 citations
01 Nov 2019
TL;DR: In this paper, the effect of air gap on braking performance of Eddy current braking system (ECB) on an electric motor was investigated and the results showed that the need for a combination of motorcycle disks with disks that match the ECB with maximum torque at 12Nm.
Abstract: Braking system by using friction is critical in electric vehicles. However, the use of excessive friction will cause a decrease in braking performance. One alternative solution is to use the Eddy current braking system (ECB). ECB is a braking system that utilizes eddy currents generated by induction when the rotor rotates due to the magnetic field produced by the stator. This study discusses the use of ECB for electric motorcycle disk braking systems. This study aims to determine the effect of air gap on braking performance of ECB on an electric motor. The finite element (FEM) method was used in ECB performance modeling. The results showed that the need for a combination of motorcycle disks with disks that match the ECB with maximum torque at 12Nm. It can be concluded that using ECB can effectively increase the braking power by reducing friction on the braking disk. It means the ECB system can extend the life of the braking disc.
4 citations
Cites background from "Mini review on the design of axial ..."
...In this type, the magnetic field used comes from DC electricity [9]....
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References
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TL;DR: The design of an eddy current brake for use as programmable viscous damper for haptic interfaces and experimental results are shown that illustrate the improvement in stability when simulating a stiff wall that is made possible using programmable eddyCurrent dampers.
Abstract: We describe the design of an eddy current brake for use as programmable viscous damper for haptic interfaces. Unlike other types of programmable brakes, eddy current brakes can provide linear, programmable physical damping that can be modulated at high frequency. These properties makes them well suited as dissipative actuators for haptic interfaces. We overview the governing physical relationships, and describe design optimization for inertial constraints. A prototype haptic interface is described, and experimental results are shown that illustrate the improvement in stability when simulating a stiff wall that is made possible using programmable eddy current dampers.
105 citations
"Mini review on the design of axial ..." refers background in this paper
...Thus, the use of pole shoe with a certain cross-section affects braking [30]....
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...Gosline [30], made a study by comparing several permanent magnets arrangements to represents the pole shoe shape, as shown in Figure 4....
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TL;DR: In this article, a 3D analytical model for axial-flux eddy-current couplings and brakes is presented, leading to closed-form expressions for the torque and the axial force.
Abstract: This paper presents a 3-D analytical model for axial-flux eddy-current couplings and brakes, leading to closed-form expressions for the torque and the axial force. The proposed model is valid under a steady-state condition (constant speed operation). It takes into account the reaction field due to induced currents in the moving conducting part. In order to simplify the analysis, we adopt the assumption of linearization at the mean radius, and the problem is then solved in 3-D Cartesian coordinates (curvature effects are neglected). The solution is obtained by solving the Maxwell equations with a magnetic scalar potential formulation in the nonconductive regions (magnets and air gap) and a magnetic field strength formulation in the conductive region (copper). Magnetic field distribution, axial force, and torque computed with the 3-D analytical model are compared with those obtained from the 3-D finite-element simulations and experimental results.
79 citations
"Mini review on the design of axial ..." refers background in this paper
...Lubin [28], conducted a study by varying conductor size....
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...While on the design side, changes in the shape or size of a conductor will influence the magnetic field and eddy currents [28], [29]....
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...Single axial ECB (a) configuration (b) magnet (c) conductor (d) eddy current [28]...
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01 Jan 2009
TL;DR: In this paper, practical design issues related to the use of high-strength neodymium-iron-boron magnets are de-scribed, and they have increasing utility in transporta- tion systems (maglev, linear and rotary motors), bearings, and in eddy-current brakes.
Abstract: In this paper, practical design issues related to the use of high-strength neodymium-iron-boron magnets are de- scribed. These magnets have increasing utility in transporta- tion systems (maglev, linear and rotary motors), bearings, and in eddy-current brakes. However, careful design must be done to utilize the full capabilities of these magnets.
77 citations
TL;DR: In this article, a 2D analytical model for the prediction of the magnetic field in permanent magnet (PM) eddy current couplings with a slotted conductor topology is proposed.
Abstract: In this paper, a 2-D analytical model for the prediction of the magnetic field in permanent magnet (PM) eddy current couplings with a slotted conductor topology is proposed. The originality of this paper lies in the fact that the influences of both the slots and the iron-core protrusions on the eddy currents induced in the slotted conductor are considered in the analytical computation, and the interactions between adjacent conducting spokes are considered. The magnetic field distribution is obtained by taking account of the eddy current reaction caused by the induced eddy currents in the slotted conductor. The moving PM field is treated as the source of a time-varying magnetic field, and both the effects of the time harmonics and spatial harmonics on the torque computation are analyzed. The results from this analytical model and nonlinear finite-element models are compared, and the effectiveness of the analytical method is demonstrated. The reason for the discrepancies between the results is discussed, and an eddy current clustering phenomenon is observed. The 2-D analytical method has the advantage of taking less computational time for a parametric study than the 3-D finite-element method, and can be a useful tool for design optimization.
68 citations
"Mini review on the design of axial ..." refers background or methods in this paper
...The combination of Ferro and non-ferrous metals as a conductor can improve braking performance [25-27]....
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...Dai [15] made hallbach arrangement design by using three permanent magnets in each segment....
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...Based, on the same design, Dai [26], conducted a study by making a model using 3D FEM....
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06 Oct 1996
TL;DR: In this article, the authors examined the possibility of using permanent magnets in the design of solid-rotor eddy current couplers and brakes, and compared and contrasted the two, in order to identify the applicability of each.
Abstract: This paper examines the possibility of using permanent magnets in the design of solid-rotor eddy current couplers and brakes. The analysis is based on a magnetostatic finite element model modified to include an eddy current distribution calculated in solid parts through an iterative process. Various rotor constructions, with a single layer of either iron, aluminum or copper or with a composite layer of iron/aluminum or iron/copper are investigated. The latter offers markedly superior performance which should in most cases justify the extra construction complexity. Magnet construction, in particular the number of poles, is also investigated. The torque characteristic and the design of couplers using permanent magnets seem to differ from their electromagnet-based counterparts, and the paper compares and contrasts the two, in order to identify the applicability of each. The model results compare satisfactorily with the test results obtained from a prototype device.
44 citations