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This article reveals the flux leakage design and modeling principle of a flux leakage controllable permanent magnet (FLC-PM) machine by considering driving cycles. The key is to obtain the relationship between flux leakage characteristics and multiple operating conditions. Based on the flux leakage controllable concept, an FLC-PM machine with an artfully designed flux leakage region is proposed. The design principle of the machine is investigated by analyzing the magnetic circuit of the machine in multiple operating conditions. The flux leakage factor is introduced to characterize the variable magnetic field in multiple operating conditions. On this basis, the mathematical model of the FLC-PM machine is deduced, and the driving characteristics of the machine are studied in detail. In order to evaluate the presented principle of the FLC-PM machine, a prototype is manufactured for experiments. Through the theoretical analysis and experimental testing, it is verified that the proposed principle is feasible and effective. [ABSTRACT FROM AUTHOR]

In this article, an integrated drive converter of segmented double-stator switched reluctance machine (SDS-SRM) with isolation and nonisolation charging capabilities for electric vehicle (EV) is presented. The proposed converter can not only reduce the number of the power switches, but also implement multiple operation modes. In nonisolation charging mode, the motor windings and existing power switches constitute a buck/boost converter to charge the battery. The appropriate rotor positions are obtained to achieve torque-free control, and the interleaved phase currents control method is introduced to reduce the charging current ripples. In isolation charging mode, the inner-stator is powered by the utility grid to drive the middle-rotor, and converts electrical energy into mechanical energy, while the outer-stator is operated in generation mode to convert mechanical energy into electrical energy. The SDS-SRM is served as a rotating transformer to transfer the electric power to charge the battery with the galvanic isolation function. A low power proof-of-concept prototype platform is built and experiments are carried out to verify the effectiveness of the proposed integrated drive converter and the corresponding control schemes. [ABSTRACT FROM AUTHOR]

Multiphase machines with a prime number of phases (five and seven) have shown better torque density than machines with other phase numbers. Unfortunately, these machines require a special stator design. Hence, this article proposes general rewinding techniques to obtain a five-phase winding from the existing standard three-phase stator frames. The proposed rewinding techniques are applied to construct a five-phase star-connected synchronous reluctance machine (SynRM 1) and a novel combined star-pentagon winding (SynRM 2). Simple mathematical formulations are introduced to compute the equivalent winding factor. The performance of five-phase SynRMs is analyzed using two-dimensional Ansys Maxwell transient simulations under the same copper volume for both healthy and faulty cases. SynRM 1 and 2 provide 6.56% and 13.35% higher torque compared to the three-phase SynRM at rated current and at optimal current angle. The torque ripple is decreased by 17% and 30%, respectively. Moreover, SynRM 1 and 2 offer a better performance at the faulty case; e.g., at one phase opened, the average torque of SynRM 1 and 2 is 82% and 108% higher compared to the three-phase SynRM. In addition, the torque ripple is reduced by about 63% and 81%. Finally, experimental results are done to validate the proposed winding techniques. [ABSTRACT FROM AUTHOR]

Vernier reluctance machine (VRM) with dc field coils in stator is a competitive rare-earth-free design for variable-speed industrial applications due to its robust structure and controllable excitation, while its torque density is relatively disadvantageous. To address this issue, this article proposes a new armature winding design method for VRM with dc field coils across two stator teeth. The key is to break the traditional winding design principle based on the flux modulation effect of fundamental dc field harmonic, and instead, reconstruct a novel harmonic winding to enhance the utilization factor of the modulated high-order dc field harmonics arising from the unique magnetomotive force distribution of dc field coils across two stator teeth. By this means, the torque density can be improved by 75.6% against the existing poor counterpart. In this article, the machine structure and operation principle are introduced, with emphasis on the high-order dc field harmonics distribution rule and its influence on the armature winding design. By finite element design and optimization, a comparative study is performed to evaluate the electromagnetic performance of VRMs using two different winding configurations with variable slot pole combinations. A prototype is fabricated and tested, and the results agree well with finite element analysis, which verifies the feasibility and advantages of the proposed winding design method. [ABSTRACT FROM AUTHOR]

This article deals with the lookup table (LUT) less sensorless control of synchronous reluctance (SyR) machines at zero and low speeds, where LUT-less stands for avoiding the use of flux-map LUTs or other predetermined machine parameters. The new signal-injection-based control scheme called the locus of incremental saliency ratio tracking is presented, where a pulsating high-frequency voltage component is used for position tracking and a second rotating signal-injection is dedicated to online estimating the incremental saliency ratio. A trajectory of constant incremental saliency ratio is used for torque regulation, resulting in stable control at all operating conditions, including overload. This despite the effect of cross-saturation, which is known to introduce position error and harm the control stability progressively with the load. The proposed scheme is validated experimentally on a 1.1-kW SyR machine test bench. Alternative LUT-less torque control laws are investigated, and their stability limits put in evidence using convergence analysis and experiments. [ABSTRACT FROM AUTHOR]

Multiphysics analysis and experimental validation of acoustic noise reduction in a high pole count, high power, switched reluctance machine (SRM), through skewing are explored in detail in this work. An iterative optimization strategy covering electromagnetic, structural, and thermal domains is proposed to investigate the effect of different skewing methods and angles on a 24-stator slot/16-rotor pole (24/16) SRM rated at 100 kW. The contributions of this work are twofold. First, electromagnetic impact, considering average torque, torque ripple, radial and tangential air gap forces, of symmetric and asymmetric skewing on stator and rotor is studied in this work. Second, the impact of skewing methods on acoustic noise and vibration performance is studied and presented in detail. The study reveals that skewing both the stator and rotor by the same amount has superior electromagnetic performance over other types of skewing. Multiphysics simulations conducted, predict a 10.5 dBA reduction in the acoustic noise, compared to a baseline design with no skew, for an optimized rotor-stator skewing angle of 13.75°. Finally, 100 kW prototypes of the baseline and the optimized skewed SRM were constructed and subjected to wide speed range testing. Simulation and test results closely follow each other and validate the effectiveness of the proposed skew design in mitigating acoustic noise and vibration in high pole count SRMs. [ABSTRACT FROM AUTHOR]

This article investigates the design methods and performance optimization of segmented-double-stator switched reluctance machine (SDS-SRM). First, two segmented U-shaped single-stator SRMs are introduced, including inner-rotor and outer-rotor constructions. In order to enhance the torque and power density, these two kinds of single-stator SRMs are combined together to constitute an SDS-SRM. Then, the relationships of torque ripple coefficient with the mechanical offset angles of the inner and outer rotor teeth are investigated to obtain the optimal rotor structure, and the corresponding conduction phase sequences for double-stator excitation mode are also analyzed. Furthermore, the flux distributions of the inner and outer stators with different coil magnetic polarities configurations are researched, and it reveals that the phase windings both on inner and outer stators with NSSNNSSN polarities have better magnetic field decoupling characteristics. To evaluate the final topology of the proposed SDS-SRM, the static magnetic characteristics and dynamic performances are presented. Finally, the SDS-SRM prototype is manufactured and tested to validate the theory and simulation analyses. [ABSTRACT FROM AUTHOR]

This article proposes an online torque ripple minimization (TRM) technique using a fuzzy system (FS)-based d-axis current design for interior permanent magnet synchronous motor (IPMSM) drives. Existing control-based TRM techniques generally employ optimization algorithms to design the dq-axis currents that attenuate the torque ripples. However, complex iterations applied for the optimization algorithms increase computational complexity, which limits the applicability of such TRM techniques under transient state of the IPMSM drives. Unlike with existing methods, the proposed TRM technique designs reference d-axis current using a computationally efficient algorithm and remarkably minimizes the torque ripples. Moreover, the reference d-axis current is designed online based on an FS to keep the stator current of the IPMSM inside the rated value, especially at the transient state. The proposed TRM strategy is validated through simulation and experimental investigations by using a MATLAB/Simulink software and a prototype IPMSM drive with TI TMS320F28335 digital signal processor. Comparative theoretical and experimental investigations prove that the proposed TRM technique is computationally efficient and ensures more reduced ripples in the electromagnetic torque and dq-axis currents with d-axis current significantly close to zero than conventional maximum torque per ampere based technique without TRM and conventional current control-based TRM technique under critical load conditions. [ABSTRACT FROM AUTHOR]

In this article, split-tooth stator slot permanent magnet (PM) machines, which have high fault-tolerant capability, are proposed. Compared with the existing 12-slot 10-pole (12S10P) stator slot PM machine, the torque can be improved by 66% by properly choosing the split tooth number and other geometric parameters. It is found that two split teeth stator slot PM machine (ST2) shows the best torque characteristics among the stator slot PM machines with different split tooth number. To further illustrate the merits and demerits of ST2, a conventional 6S4P surface mounted PM machine (SPMM) and a 6S4P variable flux reluctance machine serve as the benchmarks to compare with the 6S11P ST2, at both open circuit condition and load condition. The 6S11P ST2 shows 68% higher torque over the 6S4P VFRM. Although the torque of the 6S11P ST2 is around half of the 6S4P SPMM, the former has 70% higher torque per PM volume than the latter. Furthermore, demagnetization analyses under three-phase short-circuit and pure d-axis currents show that the 6S11P ST2 has much better demagnetization withstand capability over the 6S4P SPMM. A Prototype is manufactured and tested to validate the theoretical analyses. [ABSTRACT FROM AUTHOR]

In this article, a high-precision equivalent magnetic circuit (EMC) model is first proposed for slotted permanent-magnet (PM) limited-angle torque motor (LATM) with nonuniform teeth, which leads to potential application in swing system substituting a lower torque density of the slotless structure. By the proposed relatively fine division method of magnetic reluctance in the stator tooth-tip segments, air-gap regions, and PM poles, the proposed EMC model can fully consider armature reaction and magnetic saturation problem. Subsequently, a multiobjective optimization method based on the EMC model is proposed to improve torque performance. Finite-element analysis is employed to validate the EMC model and optimization results. Following that, a curved nonwounded tooth shape is carried out and further optimized to decrease magnetic saturation of stator teeth and significantly improve symmetry of torque profile about stable equilibrium point, compared with the traditional straight tooth shape. Finally, the slotted LATM with curved teeth is prototyped, and its experimental results are presented and discussed. The simulation and experimental data show better accuracy of torque profile improvement. [ABSTRACT FROM AUTHOR]

In this article, we present a dual-stator structure-parallel fault-tolerant machine (DSSPFTM). In this machine, the radial-flux dual-stator structure with a higher density is adopted to the fault-tolerant system. For better performance in fault condition, the combination of permanent-magnet component (PMC) and reluctance component (RC) in the rotor and large-opening slot is proposed. Because of the same poles and torque-variation principle, the PMC and RC are combined. The PMC is devised to supply most of the torque in normal conditions, while the RC provides enough self-inductance for limiting current under short-circuit (SC) occasion. Most of the flux leakage is separated from the active flux and the overload ability is improved. The design process of DSSPFTM is described in steps and details. Based on the fundamental of maximum torque under normal conditions, PMC and RC are integrated together. The end flux leakage originating from the adjacency of RC to PMC and the effect of RC length on torque are analyzed. The back-EMF, torque, inductance, loss, efficiency, and SC analysis are demonstrated. The stress and deformation distribution of the rotor and the comparison with the traditional structure are conducted. A prototype DSSPFTM is designed and manufactured. The experiments accord with simulations, indicating that the DSSPFTM with fault tolerance can improve the torque density effectively. [ABSTRACT FROM AUTHOR]

In order to increase structure compactness, critical rotor speed, and output torque of existing 12/12 bearingless switched reluctance motor (BSRM) with axial-biased permanent magnet, an improved modular permanent magnet BSRM is comprehensively investigated. First, basic structure and operation principle for torque and suspending force are briefly introduced. Second, magnetic design, including torque and suspending force, is taken into account. In addition, basic size estimation, self-starting capability, maximum suspending force, and selection of secondary air-gap are comprehensively considered in design. Third, several characteristics, such as torque, suspending force, etc., are deeply analyzed. Finally, a prototype motor is manufactured based on the above-mentioned analysis and design method. And the implemented experiment results show that the improved structure has good performance. [ABSTRACT FROM AUTHOR]

This paper proposes a new robust field-weakening approach for reluctance synchronous motors regulated by direct torque and flux control. Compared to the existing direct torque and flux control based field-weakening methods that cannot achieve maximized DC-link voltage utilization and are parameter dependent, the proposed approach contributes to improve the field-weakening performance of reluctance synchronous motor in two aspects. First, it extends the constant power speed range through autonomous stator flux reference adjustment, which maximizes the dc-link voltage utilization. Smooth transition between the maximum torque per ampere trajectory and field-weakening trajectory is also realized. Second, it enhances the parameter robustness of drives in very high-speed region by employing a torque reference adjustment scheme. This effectively avoids the instability of drives caused by machine parameter variations. The proposed approach is verified experimentally on a laboratory setup. [ABSTRACT FROM AUTHOR]

The direct torque control (DTC) method was introduced into the switched reluctance motor to reduce its inherent output torque ripple. However, the conventional DTC method produces negative torque more or less, which reduces the torque–ampere ratio of motors. This paper proposes a new DTC method by three improvements. First, the hysteresis-loop control of flux is removed. New selection rule of voltage vectors is established to reduce the torque ripple. Second, the sectors divided in electrical space are reorganized by their actual positions according to the inductance profile. The boundaries between certain sectors are calculated and updated according to real-time working conditions. Finally, the alternative voltage vectors for increasing or decreasing torque are distinguished by whether any phase is excited. Therefore, the output torque tracks the reference accurately, which reduces the torque ripple. Moreover, the negative torque is avoided by the real-time regulation of the turn-off angle, and the torque–ampere ratio is increased accordingly. Simulation and experimental results verify the demonstrated performance of the proposed DTC method. [ABSTRACT FROM AUTHOR]

This paper proposes a new position sensorless method for a direct torque control system using the inductance inflection point of a switched reluctance motor (SRM). The SRM essentially requires knowledge of the rotor position in the torque control system; this is because it generates torque by exciting the stator windings according to the rotor position. This rotor position information is an important factor used to obtain phase commutation point and to calculate instantaneous torque. Various rotor position detection methods have been used, but most of the methods increase the construction cost by requiring additional hardware and use many parameters for high-order analysis modeling, causing problems such as increasing the number of calculations. Therefore, in this paper, we propose a method using the inductance inflection point to solve these problems. It is possible to estimate the position of the rotor by detecting where the inductance inflection point occurs due to the rotor and stator overlapping with each other, and the phase commutation point and instantaneous torque can be calculated. The calculated instantaneous torque is used for direct torque control and torque ripple reduction through the torque-sharing function. The proposed method is verified through simulation and experiments. [ABSTRACT FROM AUTHOR]

A novel maximum torque per ampere (MTPA) method based on power perturbation for a field-oriented control interior permanent magnet synchronous motor (IPMSM) drive system is proposed in this study. The proposed MTPA method, which is parameter independent and can improve the motor operation at both start-up and low speed, is designed based on the power perturbation by using the signal injection in the current angle. Moreover, the influence of current and voltage harmonics to the MTPA control can be eliminated effectively. Furthermore, to enhance the robustness of the control system, an online tuning scheme for an integral-proportional controller using a new wavelet fuzzy neural network with disturbance torque feedforward control is developed where the disturbance torque is obtained from an improved disturbance torque observer. Finally, some experimental results using an IPMSM drive system based on a low-price digital signal processor are presented. From the experimental results, the proposed control approach can guarantee the control performance of the speed loop, even under a cyclic fluctuating load. [ABSTRACT FROM PUBLISHER]

In order to improve the performances of switched reluctance machines (SRMs), such as torque production and power density, combining segmented structure and hybrid-excitation is a proper and useful method. This paper develops a kind of segmented-stator hybrid-excitation SRMs (SS-HESRMs) assisted with permanent magnets (PMs) and investigates on them with different rotor pole numbers. To evaluate the effects of different rotor topologies, the static magnetic characteristics and dynamic performances of two SS-HESRMs with 12/10 and 12/8 poles are briefly presented. Moreover, both SS-HESRMs are compared with two segmented-stator SRMs (SS-SRMs) which have the same basic structure and stator/rotor pole combinations but without PMs. The results reveal that SS-HESRMs produce higher electromagnetic torque than SS-SRMs with the same stator/rotor pole configuration. The 12/10 SS-HESRM exhibits better characteristics, such as higher dynamic average torque, lower torque ripple, and higher power/torque density, than the 12/8 SS-HESRM at low-speed operation. While at high speed, the 12/8 SS-HESRM exhibits better characteristics than 12/10 SS-HESRM. The 12/10 SS-HESRM has stronger starting capability but lower steady-state speed under the same starting condition. Finally, a 12/10 SS-HESRM and a 12/8 SS-HESRM with the same structure and size are prototyped and tested to confirm the predictions. [ABSTRACT FROM PUBLISHER]

This paper presents a 12/8-pole, three-phase, modular-stator hybrid excitation switched reluctance machine (MSHSRM) assisted with permanent magnets (PMs) as well as its design consideration and performance evaluation. The basic operating principle is illustrated through a specific form of this machine, and the magnetic equivalent circuit model is built and analyzed. Then, the main parameters of the machine are optimized by the finite-element method. The static magnetic characteristics and dynamic performance of this novel machine are simulated and compared with other two SRMs, one is segmented 12/8 SRM without PM, and the other is the conventional 12/8 SRM with unsegmented structure. Finally, two motor prototypes, including one MSHSRM and one conventional SRM of the same size are manufactured. The static magnetic characteristic and dynamic operation of two motor drives are measured to confirm the predictions. The simulation and experimental results indicate that this MSHSRM has higher power and stronger load capacities than the conventional SRM in whole speed range with higher torque/power density and higher torque per ampere. [ABSTRACT FROM AUTHOR]

A switched reluctance motor (SRM) with 12/10 poles is investigated in this paper. Compared with the conventional SRMs with single mode, the machine is not only able to be worked as a six-phase motor but also could be used as a three-phase motor, which is thus named multimode SRM (MMSRM). The primary dimensions of the stator and rotor cores are calculated by considering it as a six-phase SRM with long magnetic paths, and the performances of three-phase mode with short magnetic paths are used to test the parameters. The arcs of stator and rotor pole are treated as the optimization objects to minimize torque ripple and copper loss per torque and maximize torque per ampere of the MMSRM. A function is selected to solve the multiobjective problem and the final values of arcs of stator and rotor pole are determined based on the results of finite-element method. The effects of arcs of stator and rotor pole on electromagnetic performances of MMSRM are discussed independently, and a prototype is manufactured to test the simulations. A good agreement between the simulated and measured results verifies the validity of the analytical method and results. [ABSTRACT FROM AUTHOR]

This paper presents a new simplified finite-control-set model predictive control strategy for synchronous reluctance motors operating in the entire speed range. It is a predictive control scheme that regulates the stator flux and the load angle of the synchronous reluctance motor, incorporating the ability to operate the drive in the field-weakening region and respecting the motor voltage and current limits as well as the load angle limitation needed to operate this type of motor in the maximum torque per voltage region. The proposed control strategy possesses some attractive features, such as no need for controller calibration, no weighting factors in the cost function, good robustness against parameter mismatch, and smaller computational cost compared to more traditional finite-control-set model predictive control algorithms.

Simulation and experimental results obtained using a high-efficiency synchronous reluctance motor demonstrate the effectiveness of the proposed control scheme. [ABSTRACT FROM PUBLISHER]

This paper proposes a brushless double mechanical port flux-switching permanent-magnet motor for potential application in hybrid electric vehicles. To realize the design objectives of high-torque capability, low-torque ripple, and low-magnetic coupling between the inner and outer motors, a new multilevel design optimization method is proposed to conduct a multiobjectives optimization. First, by adopting the comprehensive sensitivity approach, the whole optimization design process is divided into three levels: nonsensitive level, mild-sensitive level, and strong-sensitive level. Then, to improve the whole design efficiency, the response surface method and multiobjective genetic algorithm are applied in the mild-sensitive level and strong-sensitive level, respectively. Based on the proposed design method, a compromise design among the three design objectives is considered and realized. Finally, a prototype motor is built to verify the validity of the proposed design method and motor operation. [ABSTRACT FROM PUBLISHER]

In order to solve the coupling problem between torque and suspending force control in the conventional bearingless switched reluctance motor (SRM), this paper presents a novel bearingless SRM with a biased permanent magnet (PM). Different from the conventional bearingless SRM, the proposed bearingless SRM consists of two motors, in which each motor has two radial control degrees of freedom. In order to realize decoupling control, torque flux is completely independent from radial force flux. When the rotor center is eccentric, suspending force is generated by the control flux from the suspending force pole and the biased flux from the PM. Therefore, in order to explain the advantages of the proposed structure, conventional structures are also compared. Furthermore, the basic design method for the proposed structure and the mathematical model for the suspending force are described. The decoupling and self-starting characteristics are deeply analyzed. The validity of the proposed structure has been verified using finite-element analysis and some experimental results. [ABSTRACT FROM PUBLISHER]

This paper presents the numerical modeling of a classical switched reluctance motor (SRM) and a mutually coupled SRM (MCSRM); both have three phases with 12 slots and 8 poles. The multiphysics models have been developed, which can take into account the electromagnetic characteristics, mechanical vibration, and acoustic noise of the foregoing machines. A 2-D electromagnetic model has been used to calculate the magnetic force which is the main source of vibration of the entire motor system. The vibration of the motor is calculated by a mode superposition method, while the acoustic noise is predicted by a 3-D finite-element acoustic model. In order to validate the numerical models, experiments have been carried out. A good agreement between measured and numerical results has been observed, and it is found that the vibration and the noise levels of MCSRM are considerably lower than those of classical SRM. [ABSTRACT FROM PUBLISHER]

Minimizing cogging torque in designing axial-flux permanent-magnet (AFPM) motors is one of the main issues which must be considered during the design process. This paper presents several cost-effective magnet-skewing techniques to minimize cogging torque components in double-rotor AFPM motors. Rotor-side cogging torque minimization methods are examined in detail with major focus on magnet-skewing approach, and several cost-effective alternative skewing techniques are proposed. A detailed comparison of magnet-skewing approaches is provided. A prototype AFPM motor with different rotor structures is built based on the analyses. Analyses are then validated with experimental results, and the influence of cogging torque component on torque quality of AFPM motors is explored. The results confirm that the proposed magnet-skewing approaches can significantly reduce the cogging component as opposed to reference AFPM motor with unskewed magnets and help to improve the torque quality of the disk motors. [ABSTRACT FROM PUBLISHER]

In this paper, a novel type of hybrid reluctance motor (HRM) drive is presented. This new motor is characterized by a stator formed by a combination of independent magnetic structures, each one composed of an electromagnet, the magnetic core with one or several coils wound on it, associated with a permanent magnet disposed between their poles. The rotor has the same configuration of a switched reluctance motor (SRM) without any coil, magnets, or squirrel cage. A particular case of this HRM, with three electromagnets with permanent magnets in the stator and five salient poles in the rotor, is studied. The motor is then analyzed and simulated. Finally, experimental results are given, and this type of motor drive is compared with the SRM drives of the same size. This new type of HRM does not present cogging torque and has higher power and efficiency than an SRM of the same size. [ABSTRACT FROM PUBLISHER]

The switched reluctance machine (SRM) has certain advantages such as robustness and the absence of permanent magnets which have encouraged its use in recent years. One of its applications is as a self-excited generator. This behavior is produced when a capacitor is series or parallel connected to each single phase forming a nonlinear pseudoresonant circuit. This application can be used in isolated sites with a wind turbine for energy generation. This paper describes a novel method used for the specific design of a 1-kW self-excited SRM for wind power applications based on torque considerations. The machine volume, dimensions, finite-element analysis, model verification, simulations, and experimental results are all presented. [ABSTRACT FROM AUTHOR]

This paper presents the design and operation of a two-phase four-two pole switched reluctance motor (SRM) for a high-speed air blower. The air blower has unidirectional rotation and requires a wide positive torque region without torque dead zone. In order to achieve the requirements, a nonuniform air gap with asymmetric inductance profile is considered. For a flattop torque with a low torque ripple, the nonuniform air gap is also effective. Based on the output torque analysis at the rotor position for the given air gap, the air gap is modified to reduce the torque ripple. The optimized air gap at a given position cannot feel the effect of the air gap at a previous rotor position. Therefore, the output torque cannot fully satisfy the target torque in one optimization process. In order to satisfy the target torque and reduce the torque ripple, the second optimization process is implemented considering the output torque of the initial optimization process. The second target torque is determined by the torque error of the initial output torque and target torque of the first process. From this optimization sequence, the final air gap, as a function of the rotor position, can be determined to satisfy the torque ripple requirement. The proposed high-speed four-two pole SRM is tested to verify the high-efficiency and low-acoustic-noise characteristics. [ABSTRACT FROM PUBLISHER]

Redundant flux-switching permanent-magnet (R-FSPM) motors are a new class of brushless machines having magnets in the stator, offering high power density, simple and robust rotor structure, and good thermal dissipation conditions. This paper proposes a new control strategy for fault-tolerant operation of the R-FSPM motor drive considering the capability limitation of the power converter. The key is to operate the R-FSPM motor in the remedial mode by injecting harmonic currents, the so-called remedial injected-harmonic-current (RIHC) operation mode. Moreover, the motor losses at the existing and the proposed remedial operations are compared for evaluation. Both cosimulation and experimental results are presented, confirming that the proposed RIHC operation can offer good steady-state and dynamic performances while reducing the motor losses and the capability requirements of the power converter during fault. [ABSTRACT FROM PUBLISHER]

This paper describes the design of a high-speed three-phase switched reluctance machine to drive a compressor for the air management of a fuel-cell system for automotive applications. The machine geometry is optimized by means of a finite-element method coupled to a genetic algorithm. The performance of the optimized machine is evaluated, taking into account the iron and air-friction losses. Some theoretical and numerical results are sustained by the measured ones in the same operating conditions. [ABSTRACT FROM AUTHOR]