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Synchronous Reluctance Motors (SynRMs) have become very attractive alternatives to induction motors which have been widely used in industry in recent years. Axial-flux motor (AFM) structures have been studied in the literature as a new field. However, studies on axial-flux synchronous reluctance motors (AF-SynRMs) are very limited. In this study, optimization of an AF-SynRM has been performed to achieve optimal motor performance. In addition, the effects of the permanent magnets (PMs) have been investigated. In this design, PMs have been placed in the barriers using eight different ways, and motor performance has been examined. The placement of magnets on the barriers that are close to the air gap has an increasing effect on the average torque. However, the distorting effect on the torque ripple is seen to be quite high. In particular, the placement of magnet on all barriers improves the machine performance significantly. The negative impact on torque ripple is also low. Therefore, this study aims to provide guidance to researchers working on the design of AF-SynRMs, especially with PMs. [ABSTRACT FROM AUTHOR]

In this study, a high-power synchronous reluctance motor (SynRM) was designed for the traction motor of electric vehicle (EV) and its double-stage optimization was performed. Genetic algorithm and sensitivity analysis methods were used to obtain the best design parameters. Double-stage optimization was carried out to minimize the torque ripple and obtain the targeted torque, speed, and power values of the SynRM. In the first stage, the genetic algorithm method was used to improve the design parameters of the stator and rotor. With the improved design parameters, it was observed that the torque ripple decreased. In the second stage, the sensitivity analysis method was used. In this method, the effect of changing the skew angle of the stator on the torque ripple was investigated. The performance of the designed motor was examined in the optimization process. It was observed that the targeted torque, power, speed, efficiency, and torque ripple minimization values are successfully achieved with the best stator and rotor parameters. The results showed that SynRM produces high torque and high power with high efficiency and low torque ripple over wide speed range. It is quite proper to use the designed SynRM as a traction motor of new generation electric vehicles. [ABSTRACT FROM AUTHOR]

Energy resources are decreasing in the world and the use of electrical machines is increasing. Motor design and development studies are carried out to reduce the losses and increase the efficiency of motors, which are widely used especially in industry. In this study, Line Start Synchronous Reluctance Motor (LS-SynRM) was designed by taking an induction motor, one of the most widely used motors in the industrial field, as a reference. With its rotor cage structure feature, it can be line-start without the need of a driver. The rotor has a lot of design variables due to slots and barriers. Sensitivity analysis was used to determine the effect of design variables on performance criteria such as power factor, efficiency and torque ripple. Subsequently, Multi-Objective Genetic Algorithm (MOGA) optimization was used to find the values of the design variables that bring the motor performance closer to the optimum result. The results of the reference induction motor, initial LS-SynRM, and the optimized LS-SynRM are compared. It has been taken care to preserve the synchronization feature of the LS-SynRM and the related results are given in the analyses. It is shown that the optimized motor is in IE4 efficiency class and operates with low torque ripple. [ABSTRACT FROM AUTHOR]

In this paper, a novel linear switched reluctance motor (LSRM) is introduced in which the total electromagnetic losses and dimensions are significantly reduced compared to the conventional LSRMs. The LSRM's stator has a segmental structure, while its rotor possesses a seven pole configuration with three rotor poles equipped with the winding sets to generate the magnetic flux. The other remaining four rotor poles, i.e., auxiliary poles, are responsible for closing the magnetic flux path loop. In the proposed LSRM-auxiliary mover poles (LSRM-AMP), the flux path length is effectively reduced using the optimized provided auxiliary poles. Therefore, the required magnetomotive force (MMF) is reduced compared to the conventional LSRMs. In addition, as only half of the generated flux passes the stator segments, the dimensions of the stator segments and their corresponding weights are significantly reduced without any saturation issue. In order to verify the finite element (FE)-based performance prediction of the proposed structure, the electromagnetic operating principles and the design rules of the LSRM-AMP are separately investigated. A sensitivity analysis and comparative study for the proposed LSRM-AMP and conventional LSRM topologies are presented to show the performance and characteristics superiority of the optimized LSRM-AMP structure. [ABSTRACT FROM AUTHOR]

This work investigates the application of the adjoint variable method (AVM) to switched reluctance motors (SRMs). A MATLAB toolbox developed by the authors estimates the sensitivities of the required objective function with respect to different geometric design parameters using at most one adjoint simulation. In this work, the AVM evaluates the sensitivities of the x and y components of the magnetic flux density, the phase flux linkage, and the electromagnetic torque of switched reluctance motors with respect to teeth height, yoke thickness, teeth pole arc angle, and teeth taper angle of both stator and rotor. The nonlinearity of the motor magnetic material is taken into consideration. The estimated sensitivities using AVM are compared with those obtained using the more accurate but time intensive central finite differences (CFD). An interior-point optimization algorithm utilizes the sensitivities of the electromagnetic torque of an SRM to maximize the motor static torque profile. Structural mapping technique is used to control the geometric design parameters through the optimization process. [ABSTRACT FROM AUTHOR]

Abstract—In this work, an electromagnetic design procedure for a line-start synchronous reluctance motor is presented, and the main considerations are highlighted. To improve the steady-state performance of this motor, the geometry of the flux barriers as well as their number are optimized using an automatic optimization algorithm. For this purpose, two types of flux barriers, arc shaped and trapezoidal shaped, are formulated and studied by finite-element analysis. Analyzing the average cage torque during synchronization, effectiveness of the dq-axis rotor resistances on successful synchronization is discussed. To validate the results of this analysis, dynamic simulations are used, and the impact of the dq-axis rotor resistances on synchronization is investigated. In addition, the effect of the rotor bar position on the value of the dq-axis rotor resistances is discussed and analyzed by finite-element analysis. Finally, the impact of small pieces of permanent magnet in the flux barriers is studied. It is shown that against the permanent magnet-assisted motor, permanent magnets always enhance the motor performance; the steady-state characteristic of the line-start permanent magnet assisted motor could be deteriorated by permanent magnet. [ABSTRACT FROM PUBLISHER]

This article describes the control optimization of a slotted switched reluctance generator for low-speed applications. The machine is simulated with the finite-element method. The turn-off and turn-on angles are optimized by means of a genetic algorithm to maximize the output power and minimize the torque ripple. First, these two criteria are optimized separately with a mono-objective genetic algorithm, and then a multi-objective Pareto genetic algorithm is used. An analysis of optimized parameters and resulting current waveforms is also performed. Experimental results based on a 6/4 switched reluctance generator are also presented. [ABSTRACT FROM AUTHOR]

This article describes the design of a low speed slotted switched reluctance machine (SSRM) for wind turbine applications. The modeling and the dimensioning of the machine structure are investigated. Teeth shapes are studied by maximizing the produced torque, and then the global design is analyzed by optimizing the mass to torque ratio. The influence of the number of poles per phase is investigated, and finally a comparison with other high torque machines is carried out. Dimensions are obtained thanks to a genetic algorithm (GA) associated to the finite element method for the resolution of the electromagnetic equations. [ABSTRACT FROM AUTHOR]