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Magnetics, IEEE Transactions on

Issue 5 • Date May 2015

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  • Front cover

    Publication Year: 2015 , Article#: 0002901
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  • IEEE Transactions on Magnetics publication information

    Publication Year: 2015 , Article#: 0003001
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  • Table of contents

    Publication Year: 2015 , Article#: 0100802
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  • Bit-Patterned Magnetic Recording: Theory, Media Fabrication, and Recording Performance

    Publication Year: 2015 , Article#: 0800342
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    Bit-patterned media (BPM) for magnetic recording provides a route to thermally stable data recording at >1 Tb/in $^{mathrm {mathbf {2}}}$ and circumvents many of the challenges associated with extending conventional granular media technology. Instead of recording a bit on an ensemble of random grains, BPM comprises a well-ordered array of lithographically patterned isolated magnetic islands, each of which stores 1 bit. Fabrication of BPM is viewed as the greatest challenge for its commercialization. In this paper, we describe a BPM fabrication method that combines rotary-stage e-beam lithography, directed self-assembly of block copolymers, self-aligned double patterning, nanoimprint lithography, and ion milling to generate BPM based on CoCrPt alloy materials at densities up to 1.6 Td/in $^{mathrm {mathbf {2}}}$ . This combination of novel fabrication technologies achieves feature sizes of <10 nm, which is significantly smaller than what conventional nanofabrication methods used in semiconductor manufacturing can achieve. In contrast to earlier work that used hexagonal arrays of round islands, our latest approach creates BPM with rectangular bit cells, which are advantageous for the integration of BPM with existing hard disk drive technology. The advantages of rectangular bits are analyzed from a theoretical and modeling point of view, and system integration requirements, such as provision of servo patterns, implementation of write synchronization, and providing for a stable head–disk interface, are addressed in the context of experimental results. Optimization of magnetic alloy materials for thermal stability, writeability, and tight switching field distribution is discussed, and a new method for growing BPM islands from a specially patterned underlayer—referred to as templated growth- 14;is presented. New recording results at 1.6 Td/in $^{mathrm {mathbf {2}}}$ (roughly equivalent to 1.3 Tb/in $^{mathrm {mathbf {2}}})$ demonstrate a raw error rate $< 10^{mathrm {mathbf {-2}}}$ , which is consistent with the recording system requirements of modern hard drives. Extendibility of BPM to higher densities and its eventual combination with energy-assisted recording are explored. View full abstract»

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  • Structure of Magnetic Domain Wall in Cylindrical Microwire

    Publication Year: 2015 , Article#: 1500106
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    Within a simple model, we study magnetic domain walls (DWs) inside the inner core of the amorphous ferromagnetic microwire whose spin ordering is a core-shell structure. The interaction of the (internal stress created) outer shell of the wire on the inner core is included into the Landau-Lifshitz equation via an effective Dzyaloshinskii-Moriya-like anisotropy. The resulting DW textures are classified. The model is applicable to the nanowires of a modulated diameter (periodically constricted nanowires) as well. In that case, a core-shell magnetic structure is of the purely magnetostatic origin. Because the micromagnetic simulations of the microwires are extremely challenging, the simulations of the structured nanowires are performed with the purpose of verifying analytical predictions on the shape of the DW. View full abstract»

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  • Effects of Cu Precipitates on Magnetic Properties of Nonoriented Electrical Steel

    Publication Year: 2015 , Article#: 2001604
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    Tests to measure the effects of the precipitating size of Cu on the magnetic properties of nongrain-oriented (NGO) electrical steel were carried out. The hysteresis loss had a maximum value when the diameter of the precipitates was around the thickness of the domain wall and decreased rapidly with decreasing size of the precipitates. Alternatively, yield point (YP) rose steeply with reduction in the size of Cu precipitates. It can be confirmed that the precipitating Cu has an ability of rising over 100 MPa in YP without deteriorating core loss. Regarding the effects of Cu precipitates on the hysteresis loss, the surface tension effect might be dominant for the case in which precipitates are smaller than the domain wall thickness, and internal magnetic poles are effective for the larger precipitates. View full abstract»

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  • Effect of Anisotropy Constants on Squareness Ratio in Sr–La–Co High-Performance Sintered Ferrite Magnets at Elevated Temperatures

    Publication Year: 2015 , Article#: 2100204
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    To decrease the irreversible demagnetization of Sr–La–Co sintered ferrite magnets at elevated temperatures, it is required to remarkably improve the squareness ratio ( ${H}_{{mathbf {textit k}}}/{H}_{{ {cJ}}}$ ), where ${H}_{{ { {k}}}}$ and ${H}_{{ {cJ}}}$ are the knee field and coercivity, respectively. It is very important to find out the main reason behind the effects on ${H}_{{mathbf {textit k}}}/{H}_{mathrm {mathbf {cJ}}}$ at high temperature. Particular attention has been paid to the effect of the ratio of anisotropy constant ( ${K}_{{mathbf {textit u2}}}/{K}_{{mathbf {textit u1}}}$ ) on ${H}_{{mathbf {textit k}}}/{H}_{mathrm {mathbf {cJ}}}$ for Sr1−xLaxFe12−xCoxO19(x = 0−0.4) sintered ferrite magnets above room temperature, where ${K}_{{mathbf {textit u2}}}$ , ${K}_{{mathbf {textit u1}}}$ , and ${x}$ are the quartic and quadratic anisotropy constants, and the substituted amount, respectively. The value of ${H}_{{mathbf {textit k}}}/{H}_{mathrm {mathbf {cJ}}}$ linearly decreases as ${x}$ <- inline-formula> value increases at every temperature. Furthermore, it decreases with higher temperatures. The value of ${mathbf {K}}_{{mathbf {textit u2}}}/{mathbf {K}}_{{mathbf {textit u1}}}$ remarkably increases with increasing ${x}$ value at elevated temperatures. The value of ${H}_{{mathbf {textit k}}}/{H}_{mathrm {mathbf {cJ}}}$ linearly decreases in the order of ${x}$ value as ${K}_{{mathbf {textit u2}}}/{K}_{{mathbf {textit u1}}}$ increases for all the magnets above room temperature. Uniaxial anisotropy term ( $ {K} _{{mathbf {textit u1}}}+{ {K}}_{{mathbf {textit u2}}}$ ) has an effect on the orientation in the direction of easy magnetization. However, biaxial anisotropy term ( ${K}_{{mathbf {textit u2}}}$ /2) has two different directions of easy magnetization. The difference in easy direction of biaxial anisotropy makes an angle of $ pi $ /4 to each other. An excessive increase in ${K}_{{mathbf {textit u2}}}/{K}_{{mathbf {textit u1}}}$ is not necessarily effective to increase ${H}_{{mathbf {textit k}}}/{H}_{{ {cJ}}}$ . The decrease in ${H}_{{mathbf {textit k}}}/{H}_{{ {cJ}}}$ is mainly caused by the increase in View full abstract»

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  • Aerosol Deposition of Yttrium Iron Garnet for Fabrication of Ferrite-Integrated On-Chip Inductors

    Publication Year: 2015 , Article#: 2200206
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    We have employed aerosol deposition (AD) to deposit $39~mu text{m}$ thick polycrystalline films of yttrium iron garnet at room temperature onto sapphire at a rate of 1– $3~mu text{m}$ /min as an initial investigation of utilizing AD for fabricating ferrite-integrated on-chip inductors. We characterize the structural and magnetic properties of the as-received starting powder, as-deposited film, and a pressed puck formed from the starting powder. Results show that the films are comprised of randomly oriented polycrystalline grains with structural and magnetic properties that closely resemble that of the starting powder. Results from coating a gold single-turn inductor show an increase in inductance of 79% up to $sim 300$ MHz without affecting the $Q$ -factor. These results demonstrate AD as a promising technique for depositing thick ferrite films at high deposition rates for low-temperature fabrication of ferrite-integrated on-chip inductors. View full abstract»

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  • Effect of Cooling Rate on Crystal Orientation, and Magnetic and Magnetostrictive Properties of TbFe2-Based Alloy Treated in Semisolid State Under a High Magnetic Field

    Publication Year: 2015 , Article#: 2500706
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    The effect of cooling rate on crystal orientation, and the magnetic and magnetostriction properties of TbFe2-based alloy treated in semisolid state, were investigated experimentally with and without the application of a 11.5-T high magnetic field. With this high-field application at low cooling rates, the preferred orientation of TbFe2 phase changed direction from $langle 113rangle $ to $langle 110rangle $ , which is parallel to the field direction, and the degree of $langle 110rangle $ orientation of TbFe2 phase ${F} _{mathrm {langle 110rangle }}$ decreased with increasing cooling rate. At a 60 °C/min rate, the orientation of TbFe2 phase was randomly distributed. The maximum magnetization at 20 kOe of samples was almost the same whenever they were treated from the semisolid state with and without the high magnetic field at the same cooling rate. The maximum magnetization at 20 kOe of the sample increased with increasing cooling rate. Compared with the sample treated from the semisolid state without high magnetic field, the maximum magnetostriction at 10 kOe of the alloy was much higher when treated under the high magnetic field at the same cooling rate, and the magnetostriction of the samples at 10 kOe decreased with increasing cooling rate when the alloy was treated under high magnetic field. View full abstract»

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  • A General Write Channel Model for Bit-Patterned Media Recording

    Publication Year: 2015 , Article#: 3000612
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    In this paper, we propose a general write channel model for bit-patterned media recording by adding physically justifiable noise and feedback to the previously studied model. First, we study the noisy writing process by discussing several sources of errors causing some extra disturbances during the write process, in addition to data-dependent write synchronization errors that were studied before. Then, for this generalized model with various input and state distributions, we obtain information rate lower and upper bounds including the previous bounds as special cases. Second, a simplified feedback in the proposed channel is considered which stems from the special features of writing, and the behavior of this channel is analyzed in response to the feedback and compared mathematically and numerically with the situation, at which the feedback is ignored. View full abstract»

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  • Angular Dependence of Coercivity and Bit Error Rate Estimation for Shingled Magnetic Recording With ECC Media

    Publication Year: 2015 , Article#: 3000704
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    Shingled magnetic recording (SMR) with exchange-coupled composite media provides a feasible way by enhancing the writing capability and reducing the media switching field for achieving ultrahigh areal density of magnetic storage. However, the media switching field is dependent on the angle between the easy axis and the applied field. The adjacent track encroachment induced by this angular disturbance may happen, which could increase recording noise and lead to measurable erasure. This problem is highlighted in SMR system because of the enlarged stray field. A trapezoidal shingled writing head is modeled to explore the spatial field distribution and how the writing performance is affected by the angular dependence of media coercivity. The results show that a larger easy axis deviation and a smaller anisotropy energy density ratio of hard region will be helpful for reducing switching field to improve writing capability. The analysis also suggests that, if properly arranged, the adjacent bits can suffer minimized encroachment caused by variation of angularly induced switching field and attain a satisfactory bit error rate of as low as $ {<} {5} {times } {10}^{{-} {4}}$ . View full abstract»

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  • Estimation and Detection on Uniform Hexagonal Array Models

    Publication Year: 2015 , Article#: 3200506
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    Magnetic recording at the highest areal density on conventional granular recording media uses $sim 10$ grains to carry each bit of customer data. Efforts to reduce this number have focused on improving the resolution of the writing and reading processes and, in particular, on improving uniformity of the recording medium and on incorporating knowledge of the recording medium statistics into the detection process. This paper considers the extreme case of data detection on a perfect hexagonal array of grains. This paper looks at two aspects: 1) the estimation of the angle and positioning of the array with respect to the bit-steam and 2) the use of that information to assist data detection. At aggressive densities with very few grains per bit (GPB), the estimation proceeds well and the extra information is helpful in detection. With more GPB, the gains become small. View full abstract»

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  • Straintronics-Based Random Access Memory as Universal Data Storage Devices

    Publication Year: 2015 , Article#: 3400408
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    Nanomagnetic and spin-based memories are distinguished for their high data endurance in comparison with their charge-based peers. However, they have drawbacks, such as high write energy and poor scalability due to high write current. In this paper, we apply the straintronics principle that seeks the combination of piezoelectricity and inverse magnetostriction (Villari effect), to design a proof-of-principle 2 Kb nonvolatile magnetic memory in 65 nm CMOS technology. Our simulation results show read-access and write-cycle energies as low as 49 and 143 fJ/b, respectively. At a nominal supply level of 1 V, reading can be performed as fast as 562 MHz. Write error rates $< 10^{mathrm {-7}}$ and $10^{mathrm {-15}}$ can be obtained at 10 and 5 MHz, respectively. In addition to nonvolatility, ultralow energy per operation, and high performance, our STRs memory has a high storage density with a cell size as small as 0.2 $mu text{m}^{2}$ . View full abstract»

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  • Design of a Fast and Low-Power Sense Amplifier and Writing Circuit for High-Speed MRAM

    Publication Year: 2015 , Article#: 3400507
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    A high-speed and low-power preread and write sense amplifier (PWSA) is presented for magnetoresistive RAM (MRAM). The sense amplifier incorporates a writing circuit for MRAM bits switched via timing of precessional dynamics ( $sim $ GHz speed) in a magnetic tunnel junction (MTJ). By combining read and write functions in a single power-efficient circuit, the PWSA allows for fast read and write operations while minimizing the bit error rate after data programming. The PWSA circuit is designed based on a 65 nm CMOS technology, and the magnetic dynamics are captured by a Verilog-A compact model based on macrospin behavior for MTJs. Using the preread and comparison steps in the data program operation, we are able to reduce write power consumption by up to 50% under random data input conditions. Furthermore, using the voltage-controlled magnetic anisotropy effect for precessional switching, more than $10times $ reduction of write power and transistor size both in the memory cell and the write circuit is achieved, compared with using the spin transfer torque effect. The circuit achieves 2 ns read time, 1.8 ns write time, and 8 ns total data program operation time (consisting of two read steps, one write step, and a pass/fail check step) using this PWSA concept, and a $2times $ larger sensing margin through the current feedback circuit. View full abstract»

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  • Microwave Processing of Multilayer Chip Inductors Using MgCuZn Ferrites

    Publication Year: 2015 , Article#: 4003006
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    MgCuZn ferrites are synthesized by the microwave-hydrothermal method and are processed with varying concentrations of PbO. The nanocrystalline ferrites are sintered using microwaves at a temperature of 900 °C for 30 min. SEM pictures reveal that the grains are uniformly distributed and the addition of PbO causes a small amount of grain growth. The radio frequency behaviors ( ${mu ^{ast }}$ and ${varepsilon ^{ast }})$ of the ferrite samples are tested in the frequency range of 1 MHz to 1.8 GHz. The well-densified MgCuZn ferrite with good electromagnetic properties at high frequency is prepared by incorporation of 0.6 wt% PbO. Using this ferrite powder, the multilayer chip inductors (MLCIs) are prepared by the screen printing method. The inductors of 0.56, 0.88, and $1.44~mu text{H}$ that exhibit self-resonant frequency of 260–600 MHz are made. The size of these inductors is ${mathbf{2}}~{mathbf{mm}} times boldsymbol{ 1.2}~{mathbf{mm}} times boldsymbol{ 0.8}$ mm. The inductance and resonant frequency of MLCIs can be adjusted by changing the number of ferrite layers. View full abstract»

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  • Analysis and Optimization of a Device Intended to Reproduce a Magnetic Field Along a Path

    Publication Year: 2015 , Article#: 6000307
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    The paper shows a generalization and further development of a previous work of ours already published. We describe and analyze a kind of devices intended to create a prescribed magnetic field using a set of conductors. More precisely, we discuss a device that is capable of shaping the tangential component of the magnetic field along a specific path by controlling the current applied to each conductor. An orthogonal function decomposition is used to determine the magnitude of each current. The system performance depends on the number of conductors and their location, so we introduce a set of quality parameters, and some common geometries are evaluated upon them. These devices are intended for calibration purposes of current measuring instruments based on Ampere’s integral, although the metrological aspects are out of the scope of this paper. View full abstract»

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  • Modeling 2-D Magnetostriction in Nonoriented Electrical Steels Using a Simple Magnetic Domain Model

    Publication Year: 2015 , Article#: 6000407
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    Magnetostriction in electrical steel is a source of acoustic noise and vibration of rotating electrical machine cores. Magnetostriction of nonoriented (NO) steel under 2-D magnetization is much greater than that under unidirectional, alternating magnetization. An analytical interpretation of the relevance of 2-D magnetostriction and magnetostrictive anisotropy of NO steel based on a simple magnetic domain model is presented. The analysis helps explain the effect of anisotropy on 2-D magnetostriction measurements made on commercial NO steels with different anisotropy factors. The magnitude of the 2-D magnetostriction is shown to depend on the magnetostrictive anisotropy and magnetic Poisson’s ratio. View full abstract»

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  • Subspace Correction Method for Computing Magnetic Shields in Large Power Transformers

    Publication Year: 2015 , Article#: 7002006
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    In a large power transformer, magnetic shields of the oil tank are made of grain-oriented silicon steel laminations. The thickness of a lamination is 0.3 mm and the thickness of its coating film is only $4~{mu }text{m}$ . Accurate solution of non-linear eddy current problem in such a multi-scale structure is very challenging. This paper proposes a subspace correction method (SCM) to solve the non-linear eddy current problem in the lamination system. The method can compute 3-D eddy currents in the steel laminations and is very efficient for large-scale simulations. Numerical experiments on the TEAM benchmark model $text{P}21^{mathrm{c}}$ –M1 show good agreements between the calculated and measured data and demonstrate the competitive behavior of the SCM. View full abstract»

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  • Optimization of Jiles-Atherton Hysteresis Model Parameters Using Taguchi’s Method

    Publication Year: 2015 , Article#: 7301004
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    The parameters of Jiles-Atherton hysteresis model is optimized using Taguchi’s method. The method finds optimum values of the model parameters such that best agreement is achieved between measured and modeled hysteresis loops. The model parameters of two magnetic materials, a conventional non-oriented steel and a modern amorphous material, are calculated. The Taguchi’s method-based proposed approach is compared with particle swarm optimization (PSO), differential evolution (DE), and genetic algorithm (GA)-based approaches. The proposed approach is found to produce the minimum error between measured and modeled hysteresis loops. Taguchi’s method is also found to converge faster than PSO, DE, and GA-based methods. View full abstract»

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  • Analytical Modeling and Analysis of Surface Mounted Permanent Magnet Machines With Skewed Slots

    Publication Year: 2015 , Article#: 8104508
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    In this paper, an analytical model is developed for surface mounted permanent magnet (SMPM) machines with skewed slots via the subdomain technique and the multislice method. It takes the nonuniform distribution of flux density along the axial direction caused by slot skewing into account and can be used to obtain air-gap flux density distribution in the 3-D space. The cogging torque, flux linkage, back electromotive force (EMF), and output torque are calculated with the obtained air-gap flux density. The results calculated by the analytical model are validated by the 3-D finite element analysis. The convergence and computation time of the analytical model are investigated, and good convergence and fast calculation speed can be achieved. Based on the developed analytical model, the effects of slot skewing angle and pole arc on back EMF and output torque are researched. The analytical model can be applied to the fast optimal design and performance analysis of SMPM machines with skewed slots. View full abstract»

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  • Analysis of Novel Multi-Tooth Variable Flux Reluctance Machines With Different Stator and Rotor Pole Combinations

    Publication Year: 2015 , Article#: 8104611
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    Novel multi-tooth variable flux reluctance machines (VFRMs), which adopt doubly salient stator and rotor structure with nonoverlapping stator ac armature and dc field windings, are investigated in this paper. The rotor pole number can be any integer except the phase number and its multiples. Meanwhile, to obtain symmetrical bipolar phase flux-linkage and back electromotive force waveforms, the ratio of stator pole number to the greatest common divisor of stator- and rotor-pole numbers should be even integers. Furthermore, under the same rated copper loss and stator outer radius as well as 6-pole stator, 4-tooth per stator pole VFRMs in which the stator and rotor pole number determined by ${N}_{r}=$ nN $_{s}pm 1$ ( ${n}$ is the number of small teeth per stator pole) exhibit the highest average torque. Moreover, compared with the optimal 6/7 stator/rotor pole single-tooth VFRM, the 6/25 stator/rotor pole 4-tooth VFRM has more sinusoidal and larger back EMF, negligible cogging torque, lower torque ripple, and higher torque capability at relatively low copper loss. Similar to single-tooth VFRMs, 4-tooth VFRMs with ${N}_{r}=$ nN $_{s}pm 1$ exhibit more sinusoidal back EMF and larger torque than that of VFRMs with ${N}_{r}=$ nN $_{s},pm ,2$ . The analyses are experimentally validated by several prototype machines. View full abstract»

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  • Low Space Harmonics Cancelation in Double-Layer Fractional Slot Winding Using Dual Multiphase Winding

    Publication Year: 2015 , Article#: 8104710
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    One of the main drawbacks of nonoverlapped coils in fractional slot concentrated winding permanent magnet (PM) machines are the high eddy current losses in both rotor core and permanent magnets induced by the asynchronous harmonics of the armature reaction field. It has been shown in the literature that the reduction of low space harmonics can effectively reduce the rotor eddy current losses. This paper shows that employing a combined star-delta winding to a three-phase PM machine with fractional slot windings and with a number of slots equal to 12, or its multiples, yields a complete cancellation to the fundamental magneto-motive force (MMF) component, which significantly reduces the induced rotor eddy current. Besides, it offers a slight increase in machine torque density. A case study on the well-known 12-slot/10-pole PM machine is conducted to explore the proposed approach. With the same concept, the general $n$ -phase PM machine occupying $4n$ slots and with a dual $n$ -phase winding is then proposed. This configuration offers a complete cancelation of all harmonics below the torque producing MMF component. Hence, the induced eddy currents in both rotor core and magnets are significantly reduced. The winding connection and the required number of turns for both winding groups are also given. The concept is applied to a 20-slot/18-pole stator with a dual five-phase winding, where the stator winding is connected as a combined star/pentagon connection. The proposed concept is assessed through a simulation study based on 2-D finite element analysis. View full abstract»

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  • Analysis of Windings in Variable Reluctance Resolver

    Publication Year: 2015 , Article#: 8104810
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    In this paper, the relationship between the numbers of stator slots, winding polarities, and rotor poles for variable reluctance resolvers is derived and verified, which makes it possible for the same stator and winding to be shared by the rotors with different poles. Based on the established relationship, a simple factor is introduced to evaluate the level of voltage harmonics as an index for choosing appropriate stator slot and rotor pole combinations. With due account for easy manufacturing, alternate windings are proposed without apparent deterioration in voltage harmonics of a resolver. In particular, alternate windings with nonoverlapping uniform coils are proved to be possible for output windings in some stator slot and rotor pole combinations, which further simplify the manufacture process. Finite element method is adopted to verify the proposed design, together with experiments on the prototypes. View full abstract»

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  • Performance Analysis of a Flux-Concentrating Field-Modulated Permanent-Magnet Machine for Direct-Drive Applications

    Publication Year: 2015 , Article#: 8104911
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    This paper presents a field-modulated permanent magnet (FMPM) machine using spoke-magnet-array outer rotor for direct-drive applications. The operating principle with detailed theoretical derivation is analyzed to reveal the evidence for high torque capability of the proposed machine, just due to the utilization of effective harmonic flux adding to the contribution of air-gap fundamental flux for energy conversion. Using the finite element analysis, the performance characteristics of the proposed machine are assessed and compared with permanent magnet synchronous machine counterparts to verify the theoretical analysis. A prototype machine is also fabricated for experimental validation of the proposed machine. The analytical discussions also form an important foundation for research in various high-performance FMPM machines. View full abstract»

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  • Analysis of Air-Gap Field Modulation and Magnetic Gearing Effects in Switched Flux Permanent Magnet Machines

    Publication Year: 2015 , Article#: 8105012
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    In this paper, switched flux permanent magnet (SFPM) machines are analyzed from the perspective of the air-gap field harmonics. It is found that the modulation of the salient rotor to PM and armature reaction fields in SFPM machines is similar to that of the iron pieces to those fields in the magnetic gear and magnetically geared machine. The magnetic gearing effect is analyzed in SFPM machines with different stator/rotor pole combinations, winding configurations, and stator lamination segment types by a simple magnetomotive force-permeance model, and validated by finite-element (FE) analysis. Different from fractional-slot surface-mounted PM machines in which the working air-gap field harmonic generates >95% of the average electromagnetic torque, >95% of the average electromagnetic torque in SFPM machines having $boldsymbol {p}_{boldsymbol {s}}$ stator pole pairs and $n_{r}$ rotor poles are contributed by several dominating field harmonics, i.e., rotating ones with $vert kn_{boldsymbol {r}},pm , (textbf {2}boldsymbol {i}-textbf {1})boldsymbol {p}_{boldsymbol {s}}vert $ pole pair ( $boldsymbol {k}=textbf {1}, boldsymbol {i}=textbf {1, 2, 3}$ ) and static ones with $(2boldsymbol {i}-textbf {1})boldsymbol {p}_{boldsymbol {s}}$ pole pair ( $boldsymbol {i}=textbf {1, 2, 3}$ ). The FE predicted average static torques in SFPM machines are validated by measurements on prototype machines. View full abstract»

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IEEE Transactions on Magnetics publishes research in science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage.

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Editor-in-Chief
Pavel Kabos
National Institute of Standards and Technology