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A novel two-phase switched reluctance machine (SRM) with a stator composed of E-core structure having minimum stator core iron is proposed. The E-core stator has three poles with two poles at the ends having windings and a center pole containing no copper windings. The center stator pole in the E-core is shared by both phases during operation. The air gap around the common stator pole has constant and minimum reluctance irrespective of rotor position by its unique design, and the two remaining stator poles at the ends experience variable reluctance with respect to rotor position. The stator is constructed with two independent and physically separate E-cores, and the rotor is composed of ten poles. Other pole combinations are possible. Phase excitation in the novel SRM gives short flux paths, hence reducing the magnetomotive force required to drive the machine, resulting in significant reduction of copper wire and core losses compared to existing two-phase SRMs with flux paths that traverse the entire stator back iron. The concept and principle of operation of this novel SRM and its comparison to existing two-phase SRMs are detailed in this paper. Comparison between finite-element simulations and magnetic equivalent circuit (MEC) analysis for inductance are made and compared to experimentally measured characteristics. Furthermore, comparisons between a conventional two-phase SRM and the novel SRM are made in terms of its weight and output torque. Manufacturability and cost savings of the unique SRM structure are presented. It is shown that the E-core SRM using common stator pole has 50% less iron in the magnetic path compared to a conventional two-phase SRM. Index Terms--Brushless motor, E-core, switched reluctance machine (SRM).

This paper presents design and analysis of high-power, high-speed solid rotor synchronous reluctance motors. Different rotor forms are optimized and a new configuration which combines holes and slots is proposed. The mean torque is maximized by a cyclic algorithm coupled with finite elements method to solve electromagnetic, displacement, and thermal equations. Test results on 20-kW, 20 000-r/min, and 3-kW, 3000-r/min designed machines are compared with simulations. Index Terms--High speed, optimization, solid rotor, synchronous reluctance machine.

This paper deals with optimum design criteria for maximum torque density and minimum torque ripple of synchronous reluctance motor (SynRM) according to the rated wattage using response surface methodology (RSM). The RSM has been achieved to use the experimental design method in combination with finite element method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. The proposed procedure allows to define the rotor optimum shape for maximum torque density and minimum torque ripple starting from an existing motor or a preliminary design. Index Terms--Finite element method (FEM), response surface methodology (RSM), synchronous reluctance motor (SynRM), torque ripple.

This paper presents a new Tabu Search algorithm used to design an electric motor with the best torque density while respecting some technological constraints. Tabu Search is a metaheuristic method designed for finding approximate solution of hard combinatorial optimization problems like the design of a switched reluctance motor. A comparison of the results obtained by our algorithm shows that the best solution is obtained quickly in comparison with other approach like genetic algorithm and hybrid algorithm. Index Terms--Optimization, stochastic, switched reluctance motor (SRM), Tabu search.

The majority of existing models for estimation and control of switched reluctance machines (SRMs) ignore the dynamic effects of mutual coupling between different phases. Although this may be acceptable for some common industrial applications, such a simplification may degrade significantly the performance of the drive and the precision of the estimated quantities. In this work an enhanced representation of the SRM is introduced, by defining an appropriate finite element model of the machine. This model enables accurate estimation of rotor position and electromagnetic torque, for any current configuration. The necessity as well as the feasibility of this approach is illustrated in the ease of a three-phase, 6/4 SRM. Torque and position estimation accuracy provided by the proposed methodology is validated by measurements on a prototype three-phase 6/4 SRM. Index Terms--Angular position estimation, electromagnetic torque estimation, finite-element-based estimator, switched reluctance machine (SRM) drives.

This paper examines a model of magnetomechanical and piezoelectric coupling. This model, based on the association of the magnetoelastic and piezoelectric constitutive laws, is implemented in a transient finite element formulation. The application is the reduction of the noise emitted by switched reluctance machines by means of an active damping. The active elements are piezoelectric actuators placed on the stator, for the purpose of reducing its vibrations. The control is based on a positive position feedback regulation. Thus, an infinite impulse response filter is added to the model in order to control the piezoelectric elements depending on information of the stator vibration. Index Terms--Finite element formulation, magnetostriction, piezoelectric, vibration control.

We propose a recipe to construct a symmetric positive definite and consistent reluctance constitutive matrix to be used within discrete geometric approaches when the primal grid is generated by an enhanced subgridding of a generic hexahedral grid. We focus on a magnetostatic problem as working example. Index Terms--Cell method, discrete constitutive relations, magnetostatics, subgridding.

Particle swarm optimization (PSO) algorithm is applied to the design optimization problem of axially laminated anisotropic (ALA) rotor synchronous reluctance motor (SynRM) drive. The objective of the optimization is to maximize the developed torque while minimizing the torque ripple as well as the Ohmic and core losses for traction applications. The number of flux paths, stator tooth width, and rotor flux path width define the 3-D search space for the optimization problem. An artificial intelligence modeling approach utilizing PSO and finite element-state space (FE-SS) models is used for the characterization and design optimization of a prototype ALA rotor SynRM drive for traction applications. Index Terms--Artificial intelligence, fuzzy logic, optimization methods, reluctance machines, synchronous machines.

In this paper, the analysis, design, and implementation of a novel rotor position estimator for the control of variable-speed switched reluctance generators (SRGs) are presented. The rotor position is obtained using the unsaturated instantaneous inductance. This unsaturated inductance is estimated calculating the slope of the phase current and using a reduced-size neural network (NN) whose inputs are the average current and the saturated inductance. The proposed estimator requires less processing time than traditional methods and can be fully implemented using a low-cost DSP with very few additional analog/ digital components. The rotor position estimator presented in this paper can be applied to a wind energy conversion system where the SRG is used as a variable-speed generator. This application is currently being studied because the SRG has well-known advantages such as robustness, low manufacturing cost, and good size-to-power ratio. Simulation and experimental results are presented using a 2.5-kW 8/6-SRG prototype. Index Terms--Neural networks (NNs), position control, wind power generation.

We have developed a transverse flux linear switched reluctance motor (TFLSRM) in which 12 primary-side poles, each composed of four sectors, boost efficiency over the whole operating range. Each sector can operate independently, enhancing the robustness of the system by providing fault tolerance. We present a standard design method for the machine based on a power output equation related to the machine dimensions, air gap, force, efficiency, operating velocity, and required voltage. We illustrate the procedure by designing a sector for a three-phase, 250 W prototype TFLSRM. The method uses finite-element analysis to calculate the flux density, thrust force, and normal force versus position and current prior to construction of the prototype. Calculated and experimental results match within 5%, validating the design procedure. Index Terms--Finite-element method, linear switched reluctance motor, machine design, transverse flux motor.

Modern interior permanent magnet motors, suited to large constant-power speed ranges, have a multiple flux-barrier rotor structure and show a quite complex magnetic behavior. In this paper, the flux-current relationship of such motors is analyzed, and a simplified but effective model of the cross-saturation phenomenon is proposed and verified by experiment. In addition, new flux variables are introduced that allow a rigorous splitting of permanent-magnet (PM) and reluctance torques. It is shown that the PM contribution to torque is larger than expected from the PM no-load flux. This can lead to more accurate machine design and control strategies. Index Terms--Interior permanent-magnet (IPM) motors, permanent-magnet (PM) electrical machines, synchronous reluctance motors.

In order to produce high-efficiency motors at relatively low production costs, a layered block is made from amorphous iron sheets. From the block, stator and rotor cores of a test switched reluctance motor (SRM) are fabricated. The experimental results of the test machine are compared to another test machine made from low iron loss silicon steel type 35A300 in JIS standard. This silicon steel is equivalent to M-22, 300, and V300-35A in ANSI, BS601, and DIN46400, respectively. The validity of the test results is compared and verified through use of an analytical simulation software package. Approximately 6% improvement in efficiency is observed for the prototype SRM with the layered amorphous core material. The SRM test motor has an efficiency of 95.1% at a speed of 8500 r/min with an output of 2.4 kW. Index Terms--Amorphous iron, high-efficiency motor, switched reluctance motor.

Linear switched reluctance motor (LSRM) drives are investigated and proved in this study as an alternative actuator for vertical linear transportation applications such as a linear elevator. A one-tenth-scaled prototype elevator that is focused on a home elevator with LSRMs is designed, and extensive experimental correlation is presented for the first time in this paper. The proposed LSRM has twin stators and a set of translator poles without yoke placed between the two stators. The features of the LSRM and the prototype elevator are described. Furthermore, a control strategy for the prototype elevator is introduced consisting of four control loops, viz., 1) current, 2) force, 3) velocity, and 4) position feedback control loops. Force control of the experimental prototype elevator employs the proposed force distribution function. A trapezoidal velocity profile is introduced to control vertical travel position smoothly during ascent, descent, and stop of the elevator. Conventional proportional-integral controller is used for the current and velocity control loops and their designs are described. The proposed control strategy is dynamically simulated and experimentally correlated. The analytical and experimental results of this paper prove that LSRMs are one of the strong candidates for linear elevator propulsion drives. Index Terms--Elevator, force control, force distribution function (FDF), linear switched reluctance motor (LSRM), vertical propulsion system.

Unbalanced radial force acting on a rotor shaft is undesirable because it causes motor vibrations. However, motor vibrations can be reduced with intentionally produced shaft radial force which cancels the existing unbalanced radial forces due to a nonuniform air gap or external load. Due to its special structure, the shaft radial force and torque of a switched reluctance motor (SRM) can be separately controlled when all pole currents are controlled independently. However, control of SRM radial force is rarely discussed in the existing literature. This paper presents a scheme that produces a controlled radial force for a 12/8-pole SRM. In this scheme, mutual inductances between stator poles are included in the control model. The motor torque is controlled with the conventional method, i.e., all poles in the conduction phase are energized with the same current to produce the desired torque. Two extra poles from the descending-inductance phase are energized to produce the desired radial force. The cross-coupling torque produced by the force producing poles is compensated. The experimental results have verified that when controlled with the proposed scheme, the SRM was able to produce a controlled radial force when at standstill or running, and subjected to a load torque. Index Terms--Radial force control, switched reluctance motor (SRM).

Development of a precise dynamic model is a critical step in design and analysis of optimal control strategies for switched-reluctance machines (SRM). This paper is focused on important issues concerning the development of such models and their subsequent use in designing control strategies for SRM drives. The main goal in modeling is to provide a good accuracy over the entire speed and torque range. To achieve this objective, the following requirements need to be met: 1) a good accuracy in matching the inductance of each stator phase; 2) inclusion of mutual effects when significant overlap among phases exists; 3) inclusion of short flux-path operation in each electrical cycle when significant overlap among adjacent phases exists; and 4) capability for autocalibration to cope with parameter variations incurred by manufacturing imperfections and operational conditions. In this paper, in addition to an in-depth discussion of the above factors, a practical modeling approach along with an autocalibration strategy is presented. A simple test collects the necessary data in developing the proposed model. Inherent separation among mechanical, electrical, and control time constants has been used to develop the autocalibration process. Experimental results are presented to validate the proposed method. Index Terms--Long flux path, mutual inductance, self-inductance, short flux path, switched reluctance machines (SRMs).

In this paper, a control strategy for reduced acoustic noise and sensorless operation of a switched reluctance (SR) motor is proposed for heating, ventilation, and air conditioning (HVAC) application, where the magnitude of the dc-bus voltage is controlled as a function of speed and the motor is operated in a single-pulse mode for all speed range. The dc-bus voltage is controlled by incorporating a dc chopper between the three-phase line rectifier and a split dc-link capacitor-type four-switch power converter. Such controller reduces the acoustic noise, provides more accurate position estimation for sensorless operation, and improves the life expectancy of the motor. The algorithm is first simulated through MATLAB/SIMULINK and then tested on a four-phase 8/6-pole 4-kW SR motor. The test results of achieved acoustic noise and improved sensorless operation are presented. Through the proposed method, the acoustic noise is reduced by almost 15 dB compared to the conventional scheme at low-speed regime. The proposed method is intended to drive a fan type of load in HVAC applications, where the dynamic performance requirement is not a stringent criterion. Index Terms--Heating, ventilation, and air conditioning (HVAC) application, low acoustic noise switched reluctance (SR) motor, radial force and vibration, sensorless operation, single-pulse operation.

In this paper, we analyze mutual coupling of switched reluctance (SR) motors with even and odd numbers of phases. We illustrate that SR motors with an even number of phases produce asymmetric mutual flux in different phases. On the other hand, an SR motor with an odd number of phases produces symmetric mutual coupling in all the phases. Then, we explain a practical way of measuring the mutual flux in SR motors and present the test results for an 8/6 pole, four-phase 4 kW motor. We simulated the performance of the SR motor with and without mutual flux, thereby demonstrating the effect of mutual flux on phase current, flux, and average torque. We verified the effect of mutual flux on position estimation by simulation and experiment. We show that appropriate correction for mutual flux may improve the accuracy of estimated position by 3[degrees], which will give better performance of the drive while driven without any shaft sensors. We also show that an SR motor with an odd number of phases is a better choice than one with an even number of phases because of its symmetric mutual coupling, its ability to utilize short flux paths, and the fact that it does not require costly bipolar excitation. Index Terms--Mutual flux, mutual flux measurement, position estimation, SR motor, steady-state performance, symmetric and asymmetric mutual coupling.

An integrated team artificial-intelligence electromagnetic (T-AI-EM) environment is developed to accurately determine the performance of synchronous reluctance motors (SynRM) with axially laminated anisotropic (ALA) rotor configurations. This identifier coupled to a Fuzzy Logic optimization model is used to predict an optimal design of the machine for any given input torque. The main objective of this optimization is to minimize the torque ripple, as well as Ohmic and core losses at a given torque-speed condition. This environment is applied for the characterization and design optimization of a prototype 100-kW, 6000-rev/min ALA Rotor SynRM drive system for traction applications. The T-AI-EM environment resulted in an optimized machine design. The simulation results were compared to measured performance data for verification. Index Terms--Artificial intelligence, design optimization, hybrid electric vehicles, synchronous reluctance motors.

Dynamic modeling of switched reluctance motors (SRMs) is usually done on a per-phase basis. However, in most applications, SRMs are used with simultaneous excitation of more than one phase. Thus, a model accounting for mutual coupling in the presence of magnetic saturation is needed to predict and optimize their performance in terms of efficiency and torque ripple. This paper presents a dynamic two-phase excitation model of the SRM. Motor symmetry is used to reduce the amount of flux linkage data needed for the model. An experimental procedure to obtain the flux linkage data is described. Measured flux linkage data for the 8/6 SRM are also included. Details of the simulation model and comparison with experimental waveforms along with their implications for performance prediction are presented. Index Terms--Dynamic modeling, experimental characterization, switched reluctance motor (SRM), two-phase excitation.

Dynamic hysteretic effects of magnetic materials are usually neglected in actuators modeling. In order to take into account these effects, we coupled a two-dimensional finite-element (FE) model in an original way with a magnetic equivalent circuit by using dynamic hysteretic flux tubes (DHFT). As an example of an application, we present the model of an ultrafast switched reluctance motor, in which the control of the power converter is of major importance, and where iron losses can reach critical values. Index Terms--Eddy currents, finite-element method, magnetic hysteresis, reluctance motors.

In this paper the systematic approach to the design of a asymmetrical three-phase switched reluctance motor (SRM) with wide constant power range is described. It is shown that the SRM configuration with an unequal number of turns per phases may provide a wider constant power range than a corresponding symmetrical one. If the stator pole widths are unequal, the constant power range may be further extended. In these considerations, the maximal volt-ampere characteristics of the power converter are kept on the same level. The results are obtained using a suitable SRM model whose validity has been experimentally verified. The experimental results for the referent symmetrical SRM drive and asymmetrical one with an unequal number of turns per phase are also presented. Index Terms--Computer-aided analysis, optimal control, optimization methods, reluctance motor drives.

In this paper, we develop an illustrative, physically unified model for treating a solenoidal reluctance linear accelerator. A simplified field-based physical model is developed from basic principles and cast in a variational (Lagrangian) form. The equations of motion are presented in a convenient form for computation, from which a fast and compact numerical model is constructed that also accounts for the effects of core saturation as well as the energy exchange between the field and armature motion. The results of this model are then compared with experimental results obtained from a small-scale mass launcher apparatus. Good agreement between experimental and computed behavior has been observed. Index Terms--Coilguns, electromagnetic launchers, linear motors, reluctance machines, variational methods.

In this paper, the investigation of the nonlinear dynamics of an adjustable-speed switched reluctance motor (SRM) drive with voltage pulse width modulation (PWM) regulation is carried out. Nonlinear iterative mappings based on both nonlinear and approximately linear flux linkage models are derived, hence the corresponding subharmonic and chaotic behaviors are analyzed. Although both flux linkage models can produce similar results, the nonlinear one offers the merit of accuracy but with the sacrifice of computational time. Moreover, the bifurcation diagrams show that the system generally exhibits a period-doubling route to chaos. Index Terms--Chaos, motor drives, subharmonics, switched reluctance motors.

This paper describes two methods--one numerical, the other analytical--for analyzing an axially laminated reluctance (ALAREL) motor. The numerical method, finite-element analysis (FEA), is generally used for estimation of the motor magnetic loading and capability for given stator currents. The accuracy of the FEA prediction is confirmed by a comparison between computed and measured magnetic quantities. The analytical model allows a rapid evaluation of the flux density in different parts of the motor, as well as of the capability for given stator current. It uses a distributed parameter network. The paper compares the results obtained from this network with those obtained from FEA. The methods agree well. Finally, the paper uses the two methods to investigate the effect of the quality of the magnetic material as well as the effect on motor performance of a nonuniform distribution of the laminations in the rotor. It shows that, with grain-oriented steel and nonuniformly distributed laminations, a higher flux linkage can be obtained. Consequently, lower current is required to develop the same motor torque. Index Terms--Finite element analysis, magnetic fields, magnetic flux, modeling, optimization, parameter estimation, reluctance motors, reluctance motor drives, synchronous machines, synchronous motors.

Two disadvantages of the switched reluctance motor (SRM) are its torque ripple and acoustic noise. Previous work on vibration modes and resonant frequencies of the laminations of an 8-6 SRM is extended here to include the effects of the frame. Both a smooth frame and a ribbed frame are examined, and the presence of numerous additional vibratory modes in the ribbed frame demonstrated. Accelerometer tests behind a pole verify some of the theoretical predictions. Index Terms - Mode shape, resonant frequency, switched reluctance motor, vibration.

A fully digital control scheme is presented, based on a particular type of flux observer. This includes a quite accurate magnetic model of the motor, taking into account cross saturation. This model is first described and, then, the practically obtained control performance is shown, giving evidence to the impact of such a model on the system behavior. Index Terms - AC drives, digital control, observer-based control, synchronous reluctance drive.

An adaptive fuzzy control scheme for torque-ripple minimization of switched reluctance machines is presented. The fuzzy parameters are initially chosen randomly and then adjusted to optimize the control. The controller produces smooth torque up to the motor base speed. The torque is generated over the maximum positive torque-producing region of a phase. This increases the torque density and avoids high current peaks. The controller is robust toward errors in the rotor position information, which means inexpensive crude position sensors can be used. Detailed simulation and experimental results are presented. The controller shows good response in both cases. Index Terms - Adaptive fuzzy logic control, high-performance drive, real-time digital signal processor implementation, switched reluctance machine.

This paper addresses a basic control issue in switched reluctance motor (SRM) drives - the production of a ripple-free torque. Simple and largely model-independent conventional supply waveforms are not able to satisfy this requirement. The goal of this paper is to improve SRM dynamical performance by compensating for motor nonlinearities, while maintaining the robustness of conventional methods. The method is based on a complete parameterization of position-dependent voltage and current profiles in ripple-free operation, and on a waveform optimization to minimize power supply requirements. Furthermore, model uncertainties are included to show that the proposed strategy consistently outperforms the conventional policy. Experimental data verifying the analytical approach are included. Index Terms - Nonlinear systems, reluctance motor drives, torque control.

This study investigates the dynamic characteristics of Synchronous Reluctance Motor (SynRM), with segmental rotor structure, using finite element method in which the moving mesh technique is considered. The focus of this paper is the general property and speed response characteristic of SynRM under saturation and iron loss. Extensive experimental work has been conducted to verify the accuracy of proposed analysis method. Index Terms - SynRM, FEM, Preisach Modeling

This paper considers nonlinear adaptive control of a variable reluctance motor (VRM) in a low-velocity high-torque mode of operation. A simple dynamic model for the relationship among electric torque, rotor angular position, and phase currents is proposed. The model incorporates spline functions and a set of 'Fourier' sinusoids and captures several experimentally verified VRM characteristics, including flux saturation effects. based on this model, an adaptive controller is derived using the certainty equivalence principle. The controller provides asymptotic tracking of a desired rotor position trajectory. So-called 'torque-sharing functions' are employed to smooth the commutation among phases and to increase the peak torque available from the motor, when compared to 'hard' commutation that energizes only one phase at a time. Experimental results from a laboratory VRM provide motivation for the model and illustrate the controller's design and trajectory tracking performance. Index Terms - Adaptive control, asymptotic stability, nonlinear magnetics, numerical control, reluctance motors, rotating machine nonlinear analysis, spline functions.

In this paper, winding function method in conjunction with the coupled magnetic circuit approach are used to develop the dynamic equations of the five-phase synchronous reluctance machine in the natural frame of reference (a-b-c-d-e). The effect of third harmonic of airgap MMF is included in this development. A five-phase transformation from the (a-b-c-d-e) system to a ([d.sub.1]-[q.sub.1]-[d.sub.3]-[q.sub.3]-n) system is introduced. This transformation removes the angular dependency of the inductances. Using this transformation, equations for a five-phase synchronous reluctance machine including the third harmonic of the airgap MMF were obtained. The resulting equations are compared with the equations in the natural (a-b-c-d-e) system. Simulation traces are used to confirm the validity of the model. Finally, the developed equations are compared to the experimental results and the similarities and discrepancies identified. Index Terms - Concentrated winding, synchronous reluctance motor, third harmonic.

This paper sets forth the analysis and performance characterization of the dual-winding reluctance machine fed with direct current control winding excitation operating as a generator. Saturation effect, core and harmonic losses are included in the dynamic and steady state models of the generator feeding either an impedance or a rectifier load which give calculation results that compare favorably with the experiment. KEYWORDS: Doubly-fed reluctance machine, q-d harmonic balance, saturation effects, self-excitation.

The paper describes the dynamic performance of a wind driven reluctance generator connected to an electric network of large capacity. A controller that makes possible the regular flow of power to the network has been considered. Controller parameters that successfully suppress unwanted mechanical and electrical stresses and overshoots due to wind gust, have been estimated. The performance of the controller has also been examined for short-circuit faults at the terminals of the generators. Keywords: Reluctance generators, wind turbines, wind energy.

The phase excitation pulses of a switched reluctance motor (SRM) drive need to be properly synchronized with the rotor position for optimum torque production. Accuracy of this position information determines the efficiency and smoothness of the drive operation. This paper presents a method of analyzing the errors inherent to indirect rotor position sensing schemes. The error analysis in this paper breaks down the position error to its fundamental components in the position sensing system. As an illustration, the method is applied to two different indirect position sensing schemes. The same basic approach can be applied to evaluate other SRM position sensing schemes. The results are helpful in comparing the various sensing schemes, as well as focusing improvement efforts on the appropriate segment of the system.

The effects of compression on the magnetic properties of a steel alloy used in electromagnetic devices is investigated. The results of a case study on a switched reluctance motor are presented. It is demonstrated that compression affected the winding inductances profiles as well as the performance characteristics of the motor. The simulated performance results are verified by comparison to experimental data.

This paper describes analytical prediction and measurements for the inductance profile of a linear switched reluctance motor (LSRM). First, analytical solutions for flux density due to mover winding currents are derived, for the case when the mover is located at aligned and unaligned positions. Then, using the inductance at aligned and unaligned positions obtained from two-dimensional (2-D) analytical solutions and Fourier series expansion proposed in this paper, we predict the inductance profile of the LSRM analytically. Finally, inductance measurements are given to confirm the analysis. Index Terms--Analytical calculation, inductance profile, linear switched reluctance motor (LSRM).

This paper proposes a methodology to determine separately the peak and continuous power ratings of a switched reluctance motor (SRM) for electric propulsion of an electric vehicle (EV). The input data consist of the EV main specifications (e.g., rated and maximum velocities, vehicle mass, driving schedules). Estimation of the variations of the copper and core losses with vehicle speed and motor output power is necessary to calculate the continuous power rating. The loss variations are estimated by considering the SRM operation principles and assuming (if not known) loss values at only one operating point. Using the obtained expressions, the SRM efficiency contours can be then estimated before designing and building the SRM. The SRM thermal duty can be reduced by appropriate choice of the individual loss components in the design process. Index Terms--Electric propulsion, loss estimation, propulsion sizing, switched reluctance motors.

This paper examines the design and the performances of a permanent-magnet assisted synchronous reluctance motor (PMASRM) for wide constant-power operation. The effects of properly adding magnets into the rotor of a synchronous reluctance motor are examined by several experimental results and analyses on the prototype machines. The proposed machine can offer a large constant-power speed range, high-efficiency and high-power-factor operation in comparison to the complete synchronous reluctance motor. It was shown that the problems such as the decrease of efficiency at light-loads and the uncontrolled generator mode operation, which occur in the high-speed flux-weakening operation of the conventional PM motor drives, can be eliminated in the PM-assisted synchronous reluctance motor. Index Terms--Constant-power operation, high efficiency, permanent-magnet-assisted synchronous reluctance motor, reluctance motor.

Bearingless switched reluctance motors, which can control rotor radial positions with magnetic force, have been proposed. Bearingless switched reluctance motors have combined characteristics of switched reluctance motors and magnetic bearings. Production of radial force for rotor shaft magnetic suspension is explained with differential stator windings. Mathematical relations between motor currents and radial force are derived by considering cross coupling and fringing fluxes. Theoretical relationships are verified with experimental results at partial overlap positions. Index Terms--Bearingless motor, magnetic bearing, switched reluctance motor.

This paper is aimed to analyze the electromagnetic force characteristics of a transverse flux linear switched-reluctance motor (TFLSRM) that is applicable for track-guided ground transportation and industrial automation systems. Stability enhancements on the three-dimensional (3-D) operational behaviors and application validity of this machine will be illustrated by both the finite element analysis (FEA) and the eigenvalue analysis [1]. Besides, a supplemental comparison for flux guidance and force augmentation of linear motor with and without permanent magnet implemented will be investigated for practical consideration. Index Terms--Eigen system analysis, linear switched-reluctance motor, operational stability, transverse flux.