Showing papers on "Magneto published in 2008"
Patent•
14 Sep 2008
TL;DR: In this article, a miniature moving magnet is placed in an oscillating magnetic field, and movement of the magnet causes power to be generated, and the magnet is then turned on and off.
Abstract: Magneto mechanical systems used for wireless power reception. A miniature moving magnet is placed in an oscillating magnetic field. Movement of the magnet causes power to be generated.
198 citations
Patent•
13 Oct 2008
TL;DR: In this article, a magneto-machines system is used for wireless power transfer in the form of an electric power transformer, which is then converted to electric power by moving the magneto mechanical system.
Abstract: Wireless power transfer is received using a magneto mechanical system. Movement of the magneto mechanical system is converted to electric power.
160 citations
TL;DR: This is the first time a high-spatial-resolution image of current density is presented using MAET and a mathematical formula whereby the lead field current density may be utilized to reconstruct the distribution of the electrical impedance in a piecewise smooth object is offered.
Abstract: Primarily this report outlines our investigation on utilizing magneto-acousto-electrical-tomography (MAET) to image the lead field current density in volume conductors. A lead field current density distribution is obtained when a current/voltage source is applied to a sample via a pair of electrodes. This is the first time a high-spatial-resolution image of current density is presented using MAET. We also compare an experimental image of current density in a sample with its corresponding numerical simulation. To image the lead field current density, rather than applying a current/voltage source directly to the sample, we place the sample in a static magnetic field and focus an ultrasonic pulse on the sample to simulate a point-like current dipole source at the focal point. Then by using electrodes we measure the voltage/current signal which, based on the reciprocity theorem, is proportional to a component of the lead field current density. In the theory section, we derive the equation relating the measured voltage to the lead field current density and the displacement velocity caused by ultrasound. The experimental data include the MAET signal and an image of the lead field current density for a thin sample. In addition, we discuss the potential improvements for MAET especially to overcome the limitation created by the observation that no signal was detected from the interior of a region having a uniform conductivity. As an auxiliary we offer a mathematical formula whereby the lead field current density may be utilized to reconstruct the distribution of the electrical impedance in a piecewise smooth object.
88 citations
TL;DR: In this paper, the authors investigated the influence of the physical properties of stabilizer and substrate on the thermal stability of a high-temperature superconductor (HTS)-FCL design.
Abstract: Coated conductors (CCs) are very promising for the design of novel and efficient resistive fault current limiters (FCLs). However, a detailed knowledge about their thermal and electromagnetic behaviors in the presence of over-critical currents is crucial for their improvement. In this context, we performed finite-element magneto-thermal modeling of CCs under over-critical current on several geometries. Accordingly, we have investigated the influence of the physical properties of stabilizer and substrate on the thermal stability to improve the high-temperature superconductor (HTS)-FCL design. All simulations were performed using COMSOL Multiphysics, a commercial finite-element package, which has a built-in coupling between the thermal and electrical equations, allowing us to compute both quantities simultaneously during the solving process. Our results allow us to determine the current threshold to achieve thermal stability of HTS FCLs made with CCs.
86 citations
TL;DR: In this article, the authors investigate the generation of thermal stresses in a nonhomogeneous anisotropic solid cylinder rotating about the z-axis at a constant angular velocity in the presence of a magnetic field.
Abstract: In the present paper, we investigate the generation of thermal stresses in a nonhomogeneous anisotropic solid cylinder rotating about the z-axis at a constant angular velocity in the presence of a magnetic field. The governing equations are solved numerically using the boundary-element method (BEM) and numerical results are obtained for the variation of the temperature, displacements, and stresses along x-axis. The effect of nonhomogeneity is investigated.
43 citations
01 Jun 2008
41 citations
Proceedings Article•
01 Oct 200826 citations
Patent•
11 Mar 2008
TL;DR: In this article, a high-performance, integrated AMR sensor has compensation and flipping coils for signal conditioning of the sensor output, at least one of the coils is formed in the laminate that connects the AMR sensors with their IC within a single package.
Abstract: A high-performance, integrated AMR sensor has compensation and flipping coils for signal conditioning of the sensor output. At least one of the coils is formed in the laminate that connects the AMR sensor with its IC within a single package. As a result, the dimensions of the die area of the AMR sensor and the package size can be kept small.
24 citations
22 citations
Patent•
23 Jul 2008
TL;DR: In this paper, the authors proposed a control method for magnetorheological damping, which can dispense with coil and exterior power supply, and the conversion from the controlled structure vibration mechanical energy to magnetic field energy can be achieved only by using less materials.
Abstract: The invention relates to an application field of magnetorheological damping, and provides a control method for magnetorheological damping, which is characterized in that: an input magnetic loop is formed by adopting a giant magnetostrictive material, a permanent magnet and magnetic yokes at both ends; an output magnetic loop is composed of a permanent magnet, a magnetic yoke and a magnetorheological medium. The control method can dispense with coil and exterior power supply, and the conversion from the controlled structure vibration mechanical energy to magnetic field energy can be achieved only by using less materials; thereby the control method for magnetorheological damping has the advantages of non-energy device, large load, great damping force, rapid response, broadband and better buffering to the impact load.
22 citations
TL;DR: A new magneto-optic current sensor with a dual-orthogonal configuration is proposed and demonstrated, which can resolve the problem which value of high-current pulses is ambiguous from the Faraday rotation in the conventional magneto.
Abstract: A new magneto-optic current sensor with a dual-orthogonal configuration is proposed and demonstrated, which can resolve the problem which value of high-current pulses is ambiguous from the Faraday rotation in the conventional magneto-optic current sensor. In this dual-orthogonal configuration, the transmission axis of the polarizer makes two given angles, which are 0° and 45°, with the orientation of the s-polarized lights of two polarizing cube beam splitters. If the intrinsic linear birefringence of the sensing element is one-fourth less than the Faraday rotation generated from the high-current pulse, the measurement current influenced by it can be ignored and four outputs of the magneto-optic current sensor are in quadrature. The value of the current pulse can be calculated by an arctangent data reduction method, which can avoid the insensitive zone of the sine function, where the measurement current has a reduced accuracy. A measurement of the high-current pulse (up to 720kA) of an electric gun, with ...
Journal Article•
TL;DR: In this article, the amplitude ratios of the reflected waves are affected by magnetic field, stretch and thermal properties of the medium, and the variations of amplitude ratios with angle of incidence have been shown graphically.
Abstract: The present investigation is concerned with the reflection in thermo-microstretch elastic solid in the presence of a transverse magnetic field, at the boundary surface. The generalized theories of thermoelasticity developed by Lord and Shulman [1](L-S) and Green and Lindsay [2](G-L) theories have been used to investigate the problem. The variations of amplitude ratios with angle of incidence have been shown graphically. It is noticed that the amplitude ratios of the reflected waves are affected by magnetic field, stretch and thermal properties of the medium.
01 Feb 2008
TL;DR: In this paper, a finite element magneto-thermal modeling of coated conductors under over-critical current on several geometries was performed using COMSOL Multiphysics (R), a commercial finite element package, which has a built-in coupling between the thermal and electrical equations, allowing them to compute both quantities simultaneously during the solving process.
Abstract: Coated conductors are very promising for the design of novel and efficient Fault Current Limiter (FCL). However, before considering using them in a power grid, their thermal and electromagnetic behaviors in the presence of over-critical currents need to be investigated indetails. In this context, we performed finite element magneto-thermal modeling of coated conductors under over-critical current on several geometries. Accordingly, we have investigated the substrate electrical connectivity and thermal properties on the HTS-FCL behavior. All simulations were performed using in COMSOL Multiphysics (R), a commercial finite element package,which has a built-in coupling between the thermal and electrical equations, allowing us to compute both quantities simultaneously during the solving process. Our simulations allowed us to formulate thresholds for the current density usable in coated HTS as well as limitation capability of a device made of these new conductors.
01 Jan 2008
TL;DR: Magneto-electro-elastic as mentioned in this paperengines have been used in the 3D printing of magneto-electric transformers, e.g. for 3D laser rangefinders.
Abstract: magneto-electro-elastic 结构的 3-dimensional 夫妇方程基于哈密尔顿原则在 Hamiltonian 系统下面被导出。变量的单个种类的问题被变换成两倍种变量的问题，并且哈密尔顿正则转变被建立。通常在欧几里德几何学的空格被调查的 magneto-electro-elastic 结构的 3-dimensional 问题被变换成 symplectic 系统。同时， Lagrange 系统被变换成 Hamiltonian 系统。作为一个例子，简单地支持的机能上地分级的 magneto-electro-elastic 材料(FGMM ) 的动态特征板和管子被调查。最后，这个问题被 symplectic 算法解决。当时，结果证明排水量，电的潜力和磁性的潜在的等等的物理数量在横向的压力下面在在层之间的接口连续地变化一些另外的物理数量象压力那样，电、磁性的排水量不是连续的。当由 piezomagnetic 效果减少了时，动态僵硬被压电的效果增加。
Patent•
18 Apr 2008
TL;DR: In this paper, a magnet temperature estimating device for a rotating electric machine is proposed, which is capable of estimating the magnet temperature more easily by using a current-torque map created beforehand.
Abstract: PROBLEM TO BE SOLVED: To provide a magnet temperature estimating device for a rotating electric machine, capable of estimating the magnet temperature more easily. SOLUTION: A torque measuring part 120 measures an actual torque of a motor generator. A torque estimating part 122 estimates the torque of the motor generator, when the magneto temperature of the motor generator is a reference temperature, by using a current-torque map created beforehand. A magnet temperature estimating part 126 estimates the magnet temperature of the motor generator based on the difference of a measuring torque Ta and an estimating torque Te, by using a magnet temperature estimating map created beforehand based on a temperature characteristics of a permanent magnet. COPYRIGHT: (C)2010,JPO&INPIT
TL;DR: In this article, the authors present a Web of Science Record created on 2008-03-18, modified on 2017-05-12, for the NNM-ARTICLE-2008-003.
Abstract: Reference LNM-ARTICLE-2008-003doi:101038/nmat2153bView record in Web of Science Record created on 2008-03-18, modified on 2017-05-12
14 Nov 2008-Compel-the International Journal for Computation and Mathematics in Electrical and Electronic Engineering
TL;DR: In this article, the effect of mechanical stresses on the magnetic properties of electrical steel used in electromagnetic devices and especially in electrical machines was studied. But the results showed that the mechanical stresses degrade the properties of the electrical steel and increase the magnetization current.
Abstract: Purpose – The purpose of this paper is to find out how to model the effect of mechanical stresses on the magnetic properties of electrical steel used in electromagnetic devices and especially in electrical machines. Further, the effect of these stresses on the operation of the machines should be studied.Design/methodology/approach – The constitutive equation of the electrical steel is usually modeled as a non linear relation between the magnetic flux density and the magnetic field strength. In this research, this constitutive equation is developed to account for the mechanical stresses through a parametric relationship, the parameters of which are estimated from measurements. Further, the constitutive equation is used in a magnetomechanically coupled numerical simulation of an induction machine.Findings – The mechanical stresses degrade the properties of the electrical steel and increase the magnetization current in electrical machines. This leads to a decrease in the efficiency of these machines.Research...
01 Mar 2008
TL;DR: In this paper, a coupled magneto-superelastic analysis by the sequential approach is proposed for shape memory alloy (SMA) helical spring actuators controlled by magnetic force.
Abstract: A method of coupled magneto-superelastic analysis by the sequential approach is proposed for shape memory alloy (SMA) helical spring actuators controlled by magnetic force. The commercial finite element software ANSYS/Emag is used for the magnetic field analysis, while the one-dimensional finite element program developed by the authors is used for the analysis of superelastic behaviors of SMA helical springs. The validity of the proposed method is verified by applying the method to the analysis of actuator models utilizing SMA composite or ferromagnetic SMA helical springs and comparing the calculated results with the experimental results.
11 May 2008
TL;DR: In this paper, a new model for magneto sensitive split-drain MOSFETs is described, based on the comparison with 3D numerical simulations, it is shown that the new model can accurately predict MAGFET current imbalance and can successfully applied for simulation of magnetically controlled oscillator.
Abstract: In this paper, a new model for magneto sensitive split-drain MOSFET is describe. The model is developed on the non-quasi-static (NQS) MOS model for conventional MOSFETs, modified to include the effects the magnetic field. Based on the comparison with 3D numerical simulations, it is shown that the new model can accurately predict MAGFET current imbalance and can successfully applied for simulation of magnetically controlled oscillator.
Patent•
20 Nov 2008
TL;DR: In this paper, an electro rheologic or magneto-rheologic liquid is contained in a housing unit and a controlling unit is provided for producing an electric or magnetic field.
Abstract: The device has a function or housing unit (1), in which an electro rheologic or magneto rheologic liquid is contained. A controlling unit (17) is provided for producing an electric or magnetic field. The device has an additional heating unit (22), by which the temperature of the electro or magneto rheologic liquid is adjusted.
Patent•
05 Nov 2008
TL;DR: Signal processing circuit for voltage signals from electrodes of a magneto-inductive, flow measuring device, wherein two measuring electrodes are connected with a fully differentially working amplifier having two inputs and two outputs as mentioned in this paper.
Abstract: Signal processing circuit for voltage signals from electrodes of a magneto-inductive, flow measuring device, wherein two measuring electrodes are connected with a fully differentially working amplifier having two inputs and two outputs.
TL;DR: In this article, a detailed theoretical study of Bessel beams propagating parallel to a magnetic field in a magneto-optic medium is presented from which the Faraday effect follows.
Abstract: We present a detailed theoretical study of Bessel beams propagating parallel to a magnetic field in a magneto-optic medium. Exact solutions of the Maxwell equations are presented from which the Faraday effect follows. The mechanical properties of light and some possible effects on the medium are also analysed.
Dissertation•
01 Feb 2008
Journal Article•