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We present a nonlinear reluctance network approach for the computation of the electromotive force (EMF) waveforms of synchronous reluctance motors (SynRM) with a massive rotor or a flux barrier rotor. We model all ferromagnetic parts of the machine by nonlinear reluctances in order to take the saturation into account. The model of the motor consists of three reluctance networks: of the stator, of the rotor, and of the air gap. The originality of the work lies in the automatic computation of the topology and of the reluctance values of the reluctance network. The computation models the air gap for any relative position of the rotor and the stator; thus, the movement of the rotor can be taken into account. For any saturation level, a comparison with time-stepping finite-element results shows good agreement for the EMF fundamental, the mean torque, and the EMF and torque harmonics of order lower than the slotting ones. For a normal saturation level, the reluctance network models also accurately compute the slotting harmonics. Index Terms--Magnetic circuits, saturation, synchronous reluctance motors.

We present, for the fist time, an analytic method of making plane-magnetic field circuit calculations. The analytic expressions for the magnetic force, field strength, flux, potential difference, etc., are derived semi-empirically. They make possible a transition from the plane-parallel configuration to the plane-meridian one. The method takes into account the magnetic resistance of a steel. ,We compare all the results of calculations with appropriate experimental values and evaluate the corresponding errors. We also present a method for complete calculation of a separator's magnetic system. We describe an approximate method of finite size effects in multipole magnetic systems with axial pole disposition. Using the method of conformal mapping, we derive an analytic expression for the magnetic field in the inner domain of separators with radial pole disposition. We also define a precise limit when a multipole system with radial pole disposition coincides with a multipole system with axial pole configuration and show that, in this limit, analytic expressions obtained independently for both cases coincide. Taking into account the analytic expressions published earlier, we thus complete the description of the magnetic fields belonging to this class of magnetic systems. Index Terms--Conformal mapping, field calculation, magnetic circuit, separators.

We have developed a new magnetic circuit consisting of eight permanent magnets with special placement order. Here, we analyze the magnetic flux density distribution, the driving force distribution, and the interference force using the finite-element method. The driving sensitivity of the actuator at low frequency is nearly twice that of a conventional actuator. We have built several samples and compared their performance with simulation data. The results prove the validity of the proposed magnetic circuit and the design method. Index Terms--Finite-element method, magnetic circuit, optical pickup, six-wire suspension type actuator.

We have investigated methods of assembling large magnetic blocks from NdFeB magnets with a high value of the maximum energy product, and inserting these blocks into magnetic circuits. We found that the magnetic induction in the middle of an air gap between large opposing magnetic blocks in a closed magnetic circuit depends, in addition to other parameters, on the basic method of assembling these magnetic blocks. We compared two methods of assembly, differing in the direction in which magnetic plates approach each other. When being moved toward each other during the assembly by Method 1, magnets first repel each other. In the case of low coercivity of the magnet material, this results in their partial demagnetization. However, by using the new Method 2, where the magnets keep attracting throughout their movement together, it is possible to eliminate partial demagnetization. Index Terms--Assembly, demagnetization, magnetic circuits, magnetic separation, permanent magnets, technological innovation.

This paper proposes an integrated magnetic dc-dc converter suitable for high input voltage application. The converter is based on a coupled input-series and output-parallel dual interleaved Flyback converter concept. All the center and outer legs are gapped, and the transformers are integrated into one magnetic core with not so tight coupling. The gap is beneficial for suppressing current spike caused by the voltage mismatch between the windings. The two transformers are inversely coupled, and current ripple reduction can be achieved with suitable coupling design. A prototype with 350-450-V input and 24-V/4-A output is built. Experimental results verify the performance of the new topology. Index Terms--Flyback converter, integrated magnetic, interleaved.

The transport parameters of a spin-wave bus and a conventional electronic transmission line are compared. Results suggest the inferiority of the spin-wave bus to traditional metal interconnects in all figures-of-merits.

In this paper, the transient performance of a magnetic core fault current limiter (FCL) saturated by high temperature superconducting (HTS) dc bias winding is investigated by using both 3-D field-circuit coupled simulation and magnetic circuit analysis. A high voltage is induced on the dc HTS winding during the fault current state. The induced voltage is computed and a short circuit coil for the reduction of induced voltage is studied. The numerical computations are verified by the experiment results on an FCL prototype. Index Terms--Fault current limiter (FCL), field-circuit coupled simulation, high temperature superconductor (HTS), magnetic circuit analysis, saturated core.

Conventional filter circuits suffer from a number of limitations, including performance degradation due to capacitor parasitic inductance and the size and cost of magnetic elements. Coupled-magnetic filters have been developed that provide increased filter order with a single magnetic component, but also suffer from parasitic inductance in the filter shunt path due to imperfectly-controlled coupling of the magnetics. In this paper, we introduce a new approach to coupled-magnetic filters that overcomes these limitations. Filter sensitivity to variations in coupling is overcome by adaptively tuning the magnetic circuit for minimum rms ripple performance with feedback based on the sensed filter output ripple. This active control enables much greater robustness to manufacturing and environmental variations than is possible in the conventional 'zero-ripple' coupled-magnetic approach, while preserving its advantages. Moreover, the proposed technique also adaptively cancels the deleterious effects of capacitor parasitic inductance, thereby providing much higher filter performance than is achievable in conventional designs. The new technique is experimentally demonstrated in a dc-dc power converter application and is shown to provide high performance. Index Terms--Automatic tuning, coupled inductor filter, integrated magnetics, zero-ripple filter.

One of the primary design requirements of automotive generation systems is maximizing power density subject to the constraint of minimizing the overall system cost. However, with the progress made in the reduction of automotive drive train noise, the torque ripple of the generator has been found to be a dominant noise source under idle conditions at high electrical loads. Thus, an added design constraint is the minimization of the torque ripple produced by the machine. In order to evaluate alternative machine designs (and select an optimal), numerical tools are typically applied. In this research, a focus is placed on the creation of numerical tools that can be used to effectively search for an optimal design. A primary tool is an evolutionary algorithm (EA) that has been integrated within a customized magnetic equivalent circuit (MEC) model of the machine. The selection of an EA that is most likely to converge to an optimal solution in the least amount of time is described along with its use in selecting an optimal rotor-pole geometry. Index Terms--Alternator, evolutionary algorithm (EA), generator, magnetic circuits, optimization.

We present a high-fidelity magnetic equivalent circuit (HFMEC) inductor model that reduces the inaccuracies associated with a traditional MEC approach. The model can accurately predict the flux linkage versus current characteristic in a fraction of the time needed for finite-element analysis. The accuracy, computational efficiency, and simple inputs (consisting of only geometry and material specifications) make the model ideal for automated inductor design. Index Terms--Inductor modeling, magnetic equivalent circuits.

A multi-function superconducting device is developed, which can act as a fault current limiter and SMES to two unattached ac systems respectively and effectively. This combined equipment SMES-FCL is mainly consisted of diodes, DC/AC converter, control circuit and a superconducting coil.

Highly efficient current type power conversion system (PCS) using Inverter-Converter Bridge (ICB) energy transfer circuit is designed for realizing SMES of large scale. This PCS can control the power supplying to the utility well when the power factor is small one, however, the system goes out of control in the high power factor operations.

The QTG quadrupole magnet containing 23 QTG magnets would be used as lattice and matching quadrupoles, will be a part of the CERN Neutrino to Gran Sasso transfer line. The test results and design of the magnet are described.

The ATLAS experiment at LHC, CERN would utilize a large, superconducting, air-cored toroid magnet system, with a long barrel and two end cap toroids. The engineering design of the cryostat, vacuum vessel, thermal radiation shields and superinsulation is discussed.

The superconducting Magnet System for the ATLAS detector at the LHC at CERN comprises a Barrel 'Toroid, two End Cap Toroids and a Central Solenoid with overall dimensions of 20 m diameter by 26 m length and a stored energy of 1.6 GJ. The updated design, development and construction of the system as well as the description of the vacuum, electrical and control system are presented.

The End Cap Toroid Magnets for the ATLAS experiment at LHC, CERN is designed and manufactured. The engineering design of the cold mass is presented by indicating the status of the industrial production as well as the cold mass mechanical structure consisting of 8 coils and key stone boxes is described

A permanent magnet quadrupole (PMQ) lens with a saturated iron is one of the candidates for the final focus lens for an e(super +1)e(super -1) Linear Collider accelerator, because of its compactness and low power consumption. The first prototype of the PMQ is fabricated and investigated to have an integrated strength of 28.5 T with an overall length of 10 cm and a 7 mm bore radius.

A new fast extraction system is installed in order to extract the beam to ring 2 of the Large Hadron Collider (LHC) and the CERN Neutrino to Gran Sasso facility (CNGS), in the long straight Section LSS4 of the Super Proton Synchrotron (SPS) at CERN. The design features and parameters of the MSE septum magnets, the function of the related main equipment elements and the magnet cooling system are described.

The construction of SOLEIL, the French third generation Synchrotron radiation Source has started with the aim of starting user operation in spring 2006. The original designs to produce any kind of polarization with long period electromagnetic undulators are described as well the principal characteristics of SOLEIL and the expected brilliance performances are presented.

CEA/Saclay uses the applications of Nb3Sn magnets, which have good superconducting properties, in the fabrication of a single-aperture quadrupole magnet. The progress in manufacturing and test of the main components as well as in he design and delivery of the main tooling are discussed.

Individually powered superconducting quadrupoles with a coil box 70 mm would be installed in the LHC insertions, in areas where increased geometrical acceptance and improved field quality are required. The experience in fabrication of the pre-series magnets and the results of the initial qualification tests are described.

The LHC insertions are equipped with several different types of individually powered superconductng quadrupoles, which is based on the same principle where two welded half-shells provide the rigidity and alignment of the magnets and serve as a helium pressure vessel. The mechanical design of the LHC insertion quadrupoles, the initial experience in the assembly of the pre-series units and the alignment measurements are reported.

A study is conducted to investigate the effects of contact resistance between strands (bare and with Cr plate) in Cable-in-conduit conductors. The results show that the obtained results provide the fundamental data to simulate an electric circuit model of multi-stranded conductors and to estimate inter-strand coupling losses in the conductors.

The magnetic circuit of a transformer is surrounded by bulk high T(sub c) superconductors with high critical current density and strong magnetic shielding characteristics. The experimental results confirm that the secondary voltage and the power transfer efficiency of the transformer increased especially in the high frequency range.

The ITER toroidal field model coil is considered in terms of its manufacture, assembly and QA methods.

The normal transition event of the Large Helical Device Helical coils and subsequent quench was studied.

An ITER TF model coil conductor (DP4) was examined to determine electromagnetic and mechanical AC loss under transverse cyclic loading.

The ITER TF coil winding pack was investigated to assess the radial plate design and manufacturing issues, cost estimates and stresses were taken into consideration.

The design of a high frequency split pair coil system for the Lose Alamos Neutron Science Center by the National High Magnetic Field Laboratory is described.

The achievements of the US Home Team and International Thermonuclear Experimental Reactor collaboration for the CS model coil program are investigated.

Test results of the 460-kA Nb3Sn conductor joint for the ITER model coils are presented.

The completion of the outer module fabrication for the ITER CS model coil is discussed and the future connection to the inner module coil is considered.

The ITER relevant cable-in-conduit Nb3Sn coil was performance tested and the results are reported.

The completion of the Central Solenoid insert fabrication for the model coil program is discussed, and heat treatment procedure is reported.

The development of a high frequency split-pair coil system for the Los Alamos Neutron Science Center is discussed and coil fatigue performance is predicted.

Potential fabrication methods and welding specifications for the external cylinder of the Compact Muon Solenoid coil are described.

A common coil magnet design was investigated with regard to initial field quality optimization of body and end harmonics.

A new design and fabrication method for planar windings with multilayers is presented. This method can virtually eliminate external soldering or conductive vias, thus reducing dc resistance and increasing reliability. Compared to the previously reported folding methods for winding fabrication, this method maximizes the use of the window height and minimizes the waste of copper area in manufacturing. The winding pattern is cut using a computer numerically controlled machine, or the punching/pressing process, which is cleaner than the commonly used etching process. The whole winding assembly is completed by a folding process. The primary and secondary windings in a transformer can be interleaved, resulting in low leakage inductance. Practical examples of low-profile transformers and inductors were constructed and tested in an active-clamped forward dc-dc converter with self-driven synchronous rectifiers. Experimental results are presented to show that such transformers/inductors are particularly useful for the design of low-profile and high-power density converter modules. Index Terms - Geometry, planar windings, transformer windings, z-folding.

A modified magnetic circuit method and a 2-d finite element procedure are presented here for the analysis of d.c. permanent magnet motors with differing armature, magnet and yoke lengths including non linear material behavior of steel and permanent magnet. A 12 volt, 120 watts motor is analyzed through these methods and compared with experimental results of a prototype sample. In case of finite element analysis, commutation effects and short chording of armature winding are treated appropriately and cogging torque and voltage ripple are predicted.

A Sm[Co.sub.5] permanent magnet periodic structure was developed to generate a sinusoidal space-varying magnetic field. This device was designed to be utilized in the wiggler of a infra-red Free-Electron Laser (IR-FEL). To design the structure, finite-element computer codes that calculate magnetic fields in two and three dimensions were utilized. The results obtained from the computer simulations and the mechanical design of the built structure are presented.

The optimization of electromagnetic devices to meet an object with constraints is well understood and requires a starting point for the iterative process. Further, where there are several objects, a solution that is a compromise between the competing objects has to be accepted. Traditional exact methodology - such as gradients-based minimization of a suitable object function - for such problems is costly and therefore depends all the more on a good starting design to minimize cost. This paper makes use of fuzzy concepts in an expert system framework and proposes an efficient method for finding a reasonably approximate optimum solution for an electromagnetic system with competing objects. This may then be used as the starting solution for a more exact, but expensive process.

Giant magnetostriction of materials such as Terfenol-D rods has potential applications for electromagnetic devices. However many magnetic problems are not solved yet. For instance, Terfenol-D has low relative permeability of about 4 which is responsible for leakage flux and make it difficult to correctly route both static and dynamic flux in the rods. Thus, to ensure homogeneous magnetic field along the rod, one has to compensate for the flux leakage at the rod ends. To that purpose an extensive computer modelling effort has been performed, on a basic actuator configuration. The Finite Element Method (FEM) has been used to analyse different magnetic circuit configurations. The leakage flux is quantified by the finite element computations. It leads to low magnetic coupling factor and, as a consequence, to low efficiency. Results for different configurations are compared and lead to an optimized design of the magnetic circuits including magnetostrictive rods.