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Switched reluctance motor (SRM) is operated at high magnetic saturation to generate large torque. The flux linkage of SRM is a nonlinear function with phase current and rotor position because of the high magnetic saturation. Also, the performance of the speed controller for the SRM driver system can be negatively affected by noise, disturbances, and inertia of load torque. Therefore, the fuzzy speed controller for the SRM driver system was developed in this study. In addition, a dynamic model of SRM was simulated in Matlab/Simulink software. Based on the results obtained in this study, the speed of the SRM was controlled over a wide range of speeds including low and high speeds by the fuzzy speed controller. Furthermore, in simulation, the rotor speed was simulated depending on the reference speed. Moreover, the speed of the SRM was experimentally tested using the DS1103 Ace kit. Finally, simulation results were compared with experimental results and they were found to be consistent with each other. [ABSTRACT FROM AUTHOR]

A Permanent Magnet Reluctance Generator (PMRG) possesses important features such as simplicity and low cost. Absence of rotor winding allows the generator to run in a wide speed range. The PMRG may have potential to be used in wind power conversion systems. An asymmetric half bridge (AHB) converter may be acceptable as a classical converter topology for PMRGs and offers independent phase control. The AHB converter with a torque ripple minimization-assisted maximum power point tracking algorithm not only provides significant torque ripple reduction on the mechanical side but also allows conversion of maximum wind energy to electrical energy. The major drawback is that the AHB converter is not commercially available as a single module; hence, manual construction by combining discrete components is required. Instead, this work introduces for the first time, the use of a full bridge (FB) converter for independent phase control of the PMRG. The main advantage is that the FB converter is commercially available as a standard intelligent power module. In order to obtain unidirectional current as in the AHB converter, modified delta configuration of the phase windings has been used. The experimental results under fixed and variable wind speed conditions confirm the effectiveness of the proposed control-converter configuration. [ABSTRACT FROM AUTHOR]

Optimum performance of switched reluctance motors (SRMs) over a wide range of speed control is an essential approach for many industrial applications. However, the doubly salient structure and deep magnetic saturation make magnetization characteristics of SRMs a highly nonlinear function of rotor position and current magnitude. This, in turn, makes the control of SRM drives a challenging task. As the control of SRMs depends on the inductance profile, it requires an adaptive control technique for optimum operation over a wide range of operating speeds. This paper presents an adaptive control technique for optimum excitation of SRM drives. The proposed control technique accurately considers the effect of back-emf voltage for high- and even low-speed operation. It determines the most efficient switch-on angle as a function of motor speed and current magnitude. Moreover, the optimum switch-off angle is defined to enhance motor output torque/power without negative torque production. The proposed technique simplifies the SRM control in order to cut down the complexity and cost; it offers easy implementation and can be used for sensor and sensorless operation of SRM drives. It also provides an eligible candidate for industrial applications as the optimization strategy uses an analytical solution. For adequate modeling, the nonlinear magnetization characteristics of the SRM are obtained using finite element analysis. The SRM, converter, and control algorithm are modeled using the MATLAB/Simulink environment. The simulation results are compared with a closed-loop switch-on angle controller in order to show the feasibility of the proposed control technique. In addition, experimental results are obtained to prove the promising performance and simplicity of the proposed controller. [ABSTRACT FROM AUTHOR]

In this study, a high-speed switched reluctance machine (HS-SRM) with cobalt-iron lamination material is proposed for spindle motors, which are used in computer numerical control machines. Wide torque-speed range, high power density, high efficiency, and low cost are the crucial issues in spindle applications. Three types of electric machine candidates, the permanent magnet synchronous machine (PMSM), induction machine (IM), and switched reluctance machine (SRM), are compared with their outstanding features. The SRM spindle motor will offer a more robust, reliable, compact, and cost-effective solution compared to the IM or PMSM spindle applications. Moreover, advancement on cobalt-iron laminations gives a chance to the SRM for competing with the PMSM and IM in terms of power density and efficiency. In this study, a high-speed SRM is designed, optimized, and analyzed. Its performance metrics are obtained based on torque-speed range and efficiency over a wide speed range. The proposed SRM is compared with existing industrial products in terms of power densities. Then the design is verified via experimental study. The results show that the HS-SRM with cobalt-iron lamination material offers ultimate power density and efficiency in wide operating conditions. [ABSTRACT FROM AUTHOR]

In this study, an analytical model is proposed for natural frequency calculation and acoustic noise prediction for high speed switched reluctance machines. The developed natural frequency model results are compared with the mechanical finite element analysis results in terms of 6 different mode shapes that cause the majority of the acoustic noise in switched reluctance machines. The results show that the analytical results are consistent with the numerical method results with minimum 90% matching. Based on the natural frequency calculation model, a new acoustic noise prediction method is developed that only needs a radial force waveform as an input emerging on stator pole surfaces. The comparison of the developed and the numerical results clearly indicates that the acoustic noise level of the switched reluctance machine can be effectively found during the design process without using time-consuming numerical methods. [ABSTRACT FROM AUTHOR]

This paper presents an optimum design process and operational analysis of a permanent magnet-assisted synchronous reluctance motor (PMASynRM) as a low-cost and highly efficient consumed magnet material machine. The motor's topology is based on inserting partial permanent magnetic materials into flux barriers of an original synchronous reluctance motor (SynRM) that implicitly increase the difference between the machine's inductances, thereby increasing output torque. The procedure of rotor design as the main contribution of this paper is carefully illustrated. The rectangular shape of the flux barriers was found to achieve cost reduction and improve productivity. The impact of the permanent magnet added to the rectangular flux barriers and how it decreases the q-axis flux are described. For analytical studies, the optimum structure of a sample machine for high-power application is designed through the 2D finite element method in a Maxwell environment. For the sample machine, it is shown that the optimum number of flux barriers, optimum insulation ratio, and optimum width of permanent magnets in order to maintain the rating level of output and minimize the ripple are 4, 0.375, and 30 mm, respectively. In addition to demonstrating the operation of the motor with and without permanent magnet material, the performance of the hybrid motor is evaluated with two different permanent magnet materials, ferrite and NdFeB. Simulation results show that despite a negligible rise of ripple torque, the PMASynRM is able to achieve a higher output torque than the original SynRM with a low amount of permanent magnet material. [ABSTRACT FROM AUTHOR]

The aim of this paper is to optimize an 8/6 doubly salient switched reluctance machine using three computational intelligence methods, which include particle swarm optimization, a genetic algorithm, and differential evolution. Three cases are investigated where different parameters are considered like the stator pole arc, rotor pole arc, and ratios, which define the stator yoke and rotor thickness. The objective functions considered are the average torque and the torque-to-weight functions. The simulations are carried out using MATLAB and FEMM software. The optimal results found are compared with the initial design, and it is shown that high improvements are achieved. [ABSTRACT FROM AUTHOR]

Direct instantaneous torque control (DITC) is one way of controlling torque in switched reluctance motors. Despite the presence of DITC control, torque ripple at nominal or higher speeds is considerable due to the back emf increasing. To overcome this drawback, many converters have been proposed. In most convertors proposed for fast excitation in DITC, controlling of boost capacity is an important problem. This paper presents a DITC for a switched reluctance motor using a proposed converter to reduce the torque ripple with controlled boost capacitor automatically. The proposed converter reduces the torque ripple at rated or higher speeds and no controller requires controlling the boost capacitor. The proposed converter is compared with an asymmetric one via simulation results using MATLAB and experimental results. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of high torque ripple in switched reluctance motor (SRM) drives. A method is proposed for below the base speed operation of SRM that determines both the turn-off and the turn-on angles for reducing motor torque ripple. Determination of the turn-off angle is an offline process performed through solving a multiobjective optimization function consisting of two criteria: torque ripple and copper loss. Turn-on angle adjustment, however, is an online process based on the intersection approach of consecutive phase currents, particularly proposed in this paper. Simulation and experimental results are presented to validate the reduction in torque ripple gained from the proposed angles control scheme. [ABSTRACT FROM AUTHOR]

The electric drive system is one of the key technologies for electric vehicles. First, the energy ow of an electric vehicle is analyzed in the driving, braking, and charging working states. After that, a drive topology that can achieve 3 working states is proposed based on the driving characteristics of a switched reluctance machine. In the driving state, the boost mode of a front-end converter is used to achieve different operating conditions, including low speed with a light load or high speed with a heavy load. In the braking state, the front-end converter is used to implement smooth switching between initial excitation and braking energy feedback. In the charging state, a new power factor correction circuit is proposed, and the motor windings and power converter constitute the onboard charger, whose power factor is correctable. According to the proposed drive topology, the control strategies for 3 working states are put forward. Finally, an experimental platform is built to verify the correctness of the control strategies as well as the exibility of the whole system. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive comparison between conventional (longitudinal ux) linear switched reluctance machines (CLSRMs) and transverse ux linear switched reluctance machines (TLSRMs) so as to enable engineers to choose a structure suitable for their applications. A commonly-used single-sided CLSRM and 4 different TLSRM structures are considered for the comparison. For a fair comparison of the 2 types of LSRMs, equal dimensions, including equal length and magnetomotive force, are applied as much as possible. The analytical approach and 3-dimensional finite element analysis (FEA) are employed to obtain the performance of these machines. It is proven analytically that the CLSRM has a higher force capability compared to TLSRMs by as much as 6 times under linear B-H characteristic operating points. The results are reinforced by the FEA-based performance results. Furthermore, the CLSRMs are simpler to construct, resulting in lower manufacturing cost and thus paving an easier path for their market acceptance than TLSRMs. These results make CLSRMs the structure of choice for linear-switched reluctance motors. [ABSTRACT FROM AUTHOR]

In this study, an EI core linear actuator is proposed for horizontal movement systems. It is a transverse ux linear switched reluctance motor designed with an EI core structure geometrically. The actuator is configured into three phases and at a 6/4 pole ratio, and it has a stationary active stator along with a sliding passive translator. The stator consists of E cores and the translator consists of I cores. The actuator has a yokeless design because the stator and translator have no back iron. The E and I cores are separated from each other to provide a fault-tolerant design and decrease the weight. The proposed model is analyzed by 3D finite element method. Phase inductance, ux linkage, and axial forces are examined by magnetostatic finite element analysis and verified by analytical approximations and experimental results. Under DC 8 A phase excitation, propulsion force is 72.57 N and corresponding power consumption is 115.5 W. This has advantages for horizontal movement systems. [ABSTRACT FROM AUTHOR]

This paper presents the design and modeling of a double-stator linear switched reluctance motor for motorizing a railway channels' shunting system. The magnetic behavior of this actuator is nonlinear due to the saturation and nonlinear magnetization curves of the materials used in this actuator. For this reason, the electromagnetic quantities such as force, flux linkage, and inductance are calculated with the finite element method using the Maxwell tool. The obtained results are presented and discussed. In order to elaborate some control strategies, a new model for the proposed actuator, based on the flux and force characteristics, is validated by the simulation results using MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

This paper presents the simulation, control, and experimental results of the velocity of a double-sided, 6/4-poled, 3-phased, 8 A, 24 V, 250 W, and 250 N pull force linear switched reluctance motor (LSRM). In the simulation and experimental study, the reference velocity is constant depending on the position and time. The velocity versus the position of the translator was controlled with fuzzy logic control (FLC) and proportional-integral (PI) control techniques. The motor was controlled by PI control method with a PIC18F452 microcontroller due to its low cost. The results of the velocity of a translator were compared with the simulation results of the PI control and FLC techniques. It was seen that the PIC18F452 microcontroller is sufficient in the velocity control of the LSRM, and in the FLC method, the force and velocity ripples are lower than in the PI control method. [ABSTRACT FROM AUTHOR]

In this study, a linear switched reluctance motor (LSRM) with 250 W, 6/4 poles, 3 phases, and 24 V was controlled with a programmable logic controller (PLC). Some parameters of the LSRM were set, and for PC monitoring, software developed by the authors was used. A serial port was used for communication between the PC and the PLC. The software was developed with Visual C#.Net 2008 for monitoring and controlling. This user interference allows for controlling of the motor's travelling distance with a running strategy. The first and second destination can be defined and the system provides that the motor operates between these points continuously. The phase and velocity currents of the motor were shown and curved with the software. The existing position of the motor and the number of pulses were determined and displayed with a linear incremental encoder. The windings of the motor phases were energized depending on their position using a classical bridge converter. This PLC-controlled LSRM study leads industrial practices and the educational sector to highlight the importance of linear motion, which is used in many implementations. Furthermore, all types of LSRMs can be used in the developed system. [ABSTRACT FROM AUTHOR]

The component parts of the tested four-phase Switched Reluctance drive are described with the four-phase 8/6 structure double salient reluctance motor, the four-phase asymmetric bridge power converter and the 89C52 MCU digital controller. The conductive electromagnetic interference noise measurement equipment is described with the function of separated common-mode noise and differential-mode noise. The tested results of common-mode noise and differential-mode noise of the tested Switched Reluctance drive are presented and the tested results of frequency spectrum are given. [ABSTRACT FROM AUTHOR]

The simple structure, low manufacturing cost, rugged behavior, high torque per unit volume, and wide torque-speed range make a switched reluctance motor (SRM) very attractive for industrial applications. However, these advantages are overshadowed by its inherent high torque ripple, acoustic noise, and difficulty to control. The controlled parameters in SRM drives can be selected as the turn-on angle, the turn-off angle, and the current reference. This paper investigates the problem of optimal control parameters considering the maximum average torque, minimum copper losses, and minimum torque ripple as the main objectives in SRM drives. The use of evolutionary algorithms (EAs) to solve problems with multiple objectives has attracted much attention recently. Differential evolution (DE) is an EA that was developed to handle optimization problems over continuous domains. A multiobjective DE (MODE) technique is introduced here to find the optimal firing angles under multiple operating conditions. The simulation results carried out on a 4-phase 8/6 pole SRM show that the proposed MODE can be a reliable alternative for generating optimal control in the multiobjective optimization of SRM drive systems. [ABSTRACT FROM AUTHOR]