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The multi‐layer switched reluctance motor (SRM) is a special type of the SRM which can be utilised appropriately in high‐power applications such as electric vehicle (EV). Thermal modelling of the multi‐layer SRM is considered for the first time in the present study and a lumped parameter thermal model is introduced for quick prediction of temperature rise in this motor. In the introduced lumped thermal model, independent thermal networks are considered for different parts of the machine including frame, stator yoke, stator pole, winding, air‐gap, end‐winding, end‐cap air, rotor pole, rotor core and shaft. All details of the modelling and the required equations are given and therefore someone can use the model easily. The developed thermal model is applied to a typical two‐layer 8/6 SRM and a prototyped three‐layer 8/8 SRM and the simulation results are then compared with those derived from three‐dimensional finite element (FE) method using ANSYS FE package and experimental results. These comparisons show well high computation speed and accuracy of the lumped thermal model developed for the multi‐layer SRM. [ABSTRACT FROM AUTHOR]

Finding an optimally designed synchronous reluctance machine with desired performance among all possible combinations of the stator and rotor with different shapes of barriers requires long execution time, which is an overwhelming task. Selecting the number of flux barriers, for instance, in accordance with the pre‐designed stator has a significant effect on the torque ripple. To tackle these issues, this study presents a comprehensive design procedure of an external rotor synchronous reluctance machine suitable for an electric bike application that includes considerations such as electro‐magnetic and mechanical aspects. Dimensions of the internal stator with tapered slots are calculated. Additionally, a global parameter, insulation ratio in the q‐axis, is used to link the microscopic parameters. Seeking for the optimal design through the insulation ratio effectively reduced the number of geometric parameters involved in the rotor shape optimisation. The preliminary rotor design is used to run multi‐objective optimisation to provide further improvement to the average torque and torque ripple. Utilising the finite‐element method, thermal and structural analyses are conducted to guarantee the safe operation of the designed motor under a steady‐state condition. Finally, measurement results of a 250 W‐fabricated motor are compared with the predicted results, which validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, a novel converter is presented to improve the excitation process in switched reluctance generators (SRGs). Accumulator capacitor converter (ACC) is based on a singular scheme of flyback converters. ACC performs two main roles. First, in an initial step, it charges an accumulator capacitor with a determined value of voltage; then, during the magnetizing period, it discharges the stored energy into machine coils. Therefore, ACC provides the SRG with a determined magnetizing energy and uses the forced magnetizing phenomenon to magnetize its coils. The processes yield some outstanding superiority such as excellent operation at high speeds, simple controlling scheme, lower stress on the excitation source, etc., over conventional converters. To analyze the performance of ACC, the required analytical expressions for charging the capacitor and discharging it into the coils are developed and the constraints for switching periods are demonstrated in detail. Afterward, through MATLAB/Simulink and finite-element analysis (FEA) simulations, its operation is evaluated and compared to conventional asymmetric bridge and bifilar converters (BFCs); moreover, its test bed is assembled and tested experimentally, and its results, along with the simulation ones, validates ACC performance. [ABSTRACT FROM PUBLISHER]

A new structure for a hybrid motion switched-reluctance motor (SRM) is presented in this paper. The hybrid motion originated from the ability of the motor to operate in three modes: 1) rotary; 2) linear; and 3) rotary–linear, which can be named a new rotary–linear SRM. The design is in such a way that both rotary and linear motions can be controlled independently. The motor is composed of a three-phase 6/4 rotary SRM with Clockwise-Counterclockwise motions and a two-phase transverse flux linear SRM with forward–backward movements. The hybrid motion control does not need any decoupling control algorithm, which is an important issue in the other rotary–linear motors. In addition, a sensorless method for the motor control is provided. The motor design is performed based on the analytical approach. According to the obtained parameters, the motor 3-D model is utilized for electromagnetic assessment. The dynamic 3-D finite-element analysis is used to evaluate motor’s flux linkage, torque, speed, current, torque ripple, torque/speed, and force characteristics. The optimum operation is considered with choosing the proper dwell angle. To verify the design, a prototype is constructed in the laboratory and compared with other structures to show the performance and applicability of the proposed motor. [ABSTRACT FROM AUTHOR]

The inherent structure of double-stator switched reluctance motor (DSSRM) provides a significant improvement in energy conversion efficiency by eliminating the radial component of the forces. Reduction of the radial force (RF) in rotational motion increases efficiency and performance of the machine. This paper proposes and implements a new flat-type double-stator segmented cup-rotor SRM (DSSCR-SRM). In this structure, the shaft is placed on one bearing, which reduces the system cost and friction. The rotor structure is designed to be connected directly to the load (direct-drive system) without the shaft requirement. Moreover, the rotor can be balanced between two stators such that the resultant RFs is reduced to zero. Due to the difference between the number of turns in inner and outer stator-coils, the forces exerted on the segmented rotor will cause it to stay partially suspended. In order to improve the results and determine appropriate performance of the motor, the magnetic analysis has been done on a 3-D model. The results of analytical calculations and the finite-element method analyses are validated by testing a prototype model of the DSSCR-SRM. [ABSTRACT FROM PUBLISHER]

The double-stator switched reluctance motor (DSSRM) has a potential to produce more power per volume than other types of SRMs. This paper offers a new design strategy concentrating on power rating to calculate the dimensions of a DSSRM. The new strategy is based on dissecting the DSSRM into two inner and outer rotor SRMs. In this regard, both inner and outer rotor SRMs are designed separately, and then, the results are merged together. The characteristics of the DSSRM are achieved utilizing analytical design and 3-D finite-element analysis (FEA). In addition, the obtained results are compared with dual SRM. To determine the appropriate performance of the motor, the magnetic analysis is performed utilizing a 3-D model. In addition, to achieve optimal operation, two different winding configurations are investigated and compared with each other. Finally, a prototype of the flat-type cup-shape DSSRM with a segmented rotor is fabricated and tested in the laboratory. The results of the analytical calculations and the FEA are validated by a testing motor, which show the accuracy and the design strategy, and it can be extensible to other types of motors. [ABSTRACT FROM PUBLISHER]

This paper proposes the electromagnetic modeling, prototype realization, and test validation of a new quintuple-set switched reluctance motor (QSSRM) for high torque/ripples and high torque/volume applications. The proposed motor consists of five stator/rotor sets. Each set includes a collection of 4/4 stator/rotor poles, which can operate independently. In this machine, the two sets are energized to produce high torque and also decrease the torque ripple in comparison with the conventional switched reluctance machine (SRM). Five sets have robust interactions between each other in order to produce high torque for the motor. Furthermore, this QSSRM has some other advantages, such as isolated phases, better cooling, high-speed operation, and so on. The proposed QSSRM configuration is based on an optimum-design formula. First, the geometrical design parameters are presented. Then, an electromagnetic model of the machine has been simulated using 3-D finite-element analysis. A prototype motor has been manufactured and tested in the laboratory. The new structure has been compared with a traditional SRM. The experimental results and comparative study validate the proposed design operation. The test results indicate that the proposed structure offers an enhanced performance in terms of higher torque density. [ABSTRACT FROM AUTHOR]

Abstract—In this article, a comprehensive method is introduced to redress eccentricity fault consequences. Two main effects of eccentricity faults include considerable increase in unbalanced magnetic force and torque ripple. Dependency of unbalanced magnetic force and torque ripple on eccentricity fault level is shown, and the possibility of compensating them via controlling currents in facing poles is proved. These objectives are accomplished through a novel converter that controls currents in poles of every phase such that one pole is responsible for nullifying unbalanced magnetic force and the facing pole is in charge of torque ripple reducing. The control algorithm is analyzed in details and through finite-element method and MATLAB/Simulink (The MathWorks, Natick, Massachusetts, USA) is implemented on a 6/4 switched reluctance motor with 30% eccentricity fault level. The proposed strategy samples the flux leakage as the index both for occurrence and criterion for compensation of unbalanced magnetic force. The suggested method is designed such that there is no need to detect eccentricity fault direction, location, and type, which makes it cost effective and practical for a wide range of switched reluctance motors and applications. [ABSTRACT FROM PUBLISHER]

The purpose of this paper is to propose analytical and finite element method (FEM) designs of a novel three-phase Seven Layers Switched ReluctanceMotor (SLSRM) for the applications which dictated by the performance with the total torque per volume as a key marker indicator. The introduced motor consists of seven magnetically independent stator layers, which each layer includes a set of 4 by 4 stator/rotor poles. In this SLSRM, the three layers are energized together to produce high torque and also decrease the torque ripple in comparison with the one layer conventional SRM. Since each layer has its independent phase in the motor, the isolation problem of coils and cooling troublesome existing in conventional SRMs is solved. In addition, these types of SLSRM have some other advantages, like simpler configuration, cooling in easier way, etc.. Firstly an analytical design is carried out to illustrate the design procedure and then three-dimensional (3-D) magneto static simulation analysis of the SLSRM and the one layer SRM is performed using 3-D FEM, to obtain and verify the flux-linkage, flux density and torque profiles. Also, the proposed motor is compared with a conventional one layer SRM with a same size and volume. [ABSTRACT FROM AUTHOR]

This paper presents a new configuration for switched reluctance motor (SRM) which can be proposed as a suitable candidate for high-torque and low-flux-leakage SRMs. Unlike the conventional SRMs, this configuration has no direct windings wrapped on the stator poles. This motor consists of three different sets, and each set has one concentric independent winding, two layers of the stator poles, and three layers of the rotor poles in which the middle rotor layer acts as a core for phase winding. To evaluate the motor performance, two types of analysis, namely, numerical technique and experimental study, have been utilized. In the numerical analysis, the 3-D finite-element method is employed, whereas in the experimental study, a prototype motor has been fabricated and tested in the laboratory. Finally, experimental results are compared to conventional SRM to verify the advantages of the proposed motor and show its applicability. [ABSTRACT FROM PUBLISHER]

This article presents a new and novel method which is designed to detect the rotor position at standstill and at low speeds in switched reluctance motor. Since the inductance parameter plays a significant role both in the steady state and in the dynamic characteristics of an electromagnetic device, the rotor position can be determined using inductance bridge systems to measure unknown inductance and resistance values. In this method we use motor winding in Maxwell-Wien Bridge, with the standard capacitor and the resistor in parallel with it adjusted to achieve balance in an aligned position when the maximum inductance occurs. The supply voltage, in conjunction with the drive transistor, produces short pulses for this AC bridge. The condition of the balanced bridge v0 = 0 leads to the relation between the impedances of the bridge branches. The phase inductance varies with the rotor position. Therefore the motor goes into an unaligned position and the Maxwell-Wien Bridge goes into an unbalanced condition thus causing variation in the state of the bridge output. It then continues to sense the rotor position with the motor running by applying the same procedure, but only to the un-energised phases winding. The simulation and experimentally obtained results demonstrate the feasibility and practicability of this method. [ABSTRACT FROM AUTHOR]

In this article, a novel view of airgap magnetic field analysis of a switched reluctance motor under mixed eccentricity to provide a precise fault diagnosis based on the three-dimensional finite element method is presented. The analytical nature of this method makes it possible to simulate a reliable and precise model by considering the end effects and axial fringing effects. The results of the three-dimensional finite element analysis of a 6/4 switched reluctance motor, such as flux linkages, terminal inductance per phase, and static torque for various eccentric motor conditions, are obtained, evaluated, and discussed. The diagnostic evaluation is based on monitoring these parameter variations and analyzing the shape of the self-inductance in the stator windings via the multiple signal classification pseudo-spectrum. Fault analysis and detection in a switched reluctance motor demonstrate that the presented scheme can assure the detection reliability and sensitivity of an eccentricity fault in a switched reluctance motor. To the best knowledge of the authors, such an analysis has not been carried out previously. [ABSTRACT FROM AUTHOR]

In this article, a novel view of switched reluctance motor analysis under eccentricity fault for providing the precise and reliable model is presented. It then continues with describing the performance characteristics and comparison results of a six-by-four switched reluctance motor with static rotor eccentricity utilizing three-dimensional finite element analysis. The results of the three-dimensional finite element analysis for a 6/4, 20-W switched reluctance motor including flux-linkages, terminal inductance per phase, mutual inductances, and static torque for various eccentric motor conditions by considering the end effects and axial fringing fields for simulating reliable model, are obtained and presented. Finally, the comparison of these results with the results obtained for the same motor profile by utilizing the two-dimensional finite element method are presented and explained. [ABSTRACT FROM AUTHOR]

Examines the configuration of a switched reluctance motor (SRM). Comparison between prototype motor and SRM; Mechanism of torque production; Types of reluctance motor.

Summary: In comparison to one‐layer switched reluctance motor (SRM), a multi‐layer SRM is able to produce much larger output power and it can be considered as a good candidate for high‐power electric machine. For a multi‐layer SRM, different layers have the same performances and they are completely independent from electromagnetic point of view. Therefore, analysis of one layer can be only carried out to determine the electromagnetic characteristics of the multi‐layer SRM. In the present paper, a fast and simple magnetic equivalent circuit (MEC) model is introduced for one‐layer SRM and it is then used for performance prediction of the multi‐layer SRM. Due to high torque ripple of the SRM, a simple solution is suggested for different types of the multi‐layer SRM by which torque ripple of this motor can be reduced significantly. To evaluate the done modeling and the suggested torque ripple method, simulation results are presented for a typical multi‐layer 8/6 SRM. [ABSTRACT FROM AUTHOR]