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This manuscript examines the output characteristics of a dual three-phase synchronous reluctance motor (DT-SynRM) according to two winding arrangements under normal and half-control modes. In the case of the DT-SynRM, it can operate by using all of the dual three-phase systems (the normal control) or one of the dual three-phase systems (the half control). In this paper, conventional winding function theory (WFT) is applied, because the output characteristic can be predicted by the inductance behavior. According to the WFT, the inductance value can be affected by the winding function, the turn function, and the inverse air gap function. As a result, the rotor barrier shape as well as the winding configuration are the most important factors that have an effect on the performance of the DT-SynRM. Therefore, the effect of the rotor barrier design on the performance is analyzed when the winding configuration and control mode are different. Finally, the validity of the torque characteristic is substantiated through experimental verification. [ABSTRACT FROM AUTHOR]

This paper introduces a decoupled unknown input observer (DUIO) for Takagi-Sugeno (T-S) systems, designed specifically for the synchronous reluctance motor (SynRM). The proposed DUIO method demonstrates enhanced robustness and accuracy in state estimation by effectively decoupling the influence of unknown inputs from the estimation error dynamics. Furthermore, the DUIO exhibits superior performance compared to the proportional integral observer (PIO) and the proportional multi-integral observer (PMIO) presented in previous studies, without the need for prior knowledge of the unknown input form or assumptions regarding its boundedness. Stability conditions, achieved using the quadratic Lyapunov function, are expressed as linear matrix inequalities (LMIs), which ensure asymptotic convergence of the estimation error. The effectiveness of the DUIO method is further validated in various scenarios through hardware-in-the-loop (HIL) implementation. This innovative approach significantly enhances the accuracy and reliability of SynRM state estimations and unknown input detections. [ABSTRACT FROM AUTHOR]

In this study, a novel composite speed controller combining a sliding-mode speed controller with a disturbance observer is proposed for the vector-controlled synchronous reluctance motor (SynRM) drive system. The proposed composite speed controller employs the generalized super-twisting sliding-mode (GSTSM) algorithm to construct both the speed controller and the disturbance observer. The GSTSM speed controller is utilized to stabilize the speed tracking error dynamics in finite time, while the GSTSM disturbance observer compensates for the total disturbance in the speed tracking error dynamics, which includes external disturbances and parametric uncertainties. Under the framework of the constant direct-axis current component vector control strategy for the SynRM drive system, comparative simulation studies are conducted among the standard STSM speed controller, the GSTSM speed controller, the composite speed controller using a GSTSM speed controller and a standard STSM disturbance observer, and the proposed composite speed controller. The effectiveness and superiority of the proposed composite speed controller are verified through simulation results. [ABSTRACT FROM AUTHOR]

This paper introduces a decoupled unknown input observer (DUIO) for Takagi-Sugeno (T-S) systems, designed specifically for the synchronous reluctance motor (SynRM). The proposed DUIO method demonstrates enhanced robustness and accuracy in state estimation by effectively decoupling the influence of unknown inputs from the estimation error dynamics. Furthermore, the DUIO exhibits superior performance compared to the proportional integral observer (PIO) and the proportional multi-integral observer (PMIO) presented in previous studies, without the need for prior knowledge of the unknown input form or assumptions regarding its boundedness. Stability conditions, achieved using the quadratic Lyapunov function, are expressed as linear matrix inequalities (LMIs), which ensure asymptotic convergence of the estimation error. The effectiveness of the DUIO method is further validated in various scenarios through hardware-in-the-loop (HIL) implementation. This innovative approach significantly enhances the accuracy and reliability of SynRM state estimations and unknown input detections.

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]

This paper proposes a new design for line-start operation of synchronous reluctance motors. In the past years, synchronous reluctance motors have been studied by many researchers. Due to high efficiency, they have gained increasing interest because in the synchronous operation, there is limited losses in the rotor. On the other hand, line-start operation of the synchronous reluctance motors is an important challenge that can make this type of the motors popular in many applications. However, line-start operation techniques should not considerably affect the steady-state characteristics of the motor. In the proposed design, the arrangement, size and shape of the rotor conductor bars are designed based on the rotor magnetic circuit difference between induction and reluctance synchronous motors. Complete assessment of the motor parameters are examined using finite element analysis. The proposed structure improves the starting characteristics of the motor. Moreover, power factor of the proposed motor is slightly increased in comparison to that of conventional line-start synchronous reluctance motors. The results obviously show effectiveness of the proposed line-start operation strategy for the synchronous reluctance motors. Finally, experimental verification are also included to confirm the finite element analysis results. [ABSTRACT FROM AUTHOR]

This paper contains research on the development of a fault-tolerant six-phase synchronous reluctance motor (SynRM) based on the stator adopted from a general-purpose three-phase induction motor. In the design and calculation process, an extended Clarke transformation was developed for a six-phase asymmetrical system. To verify the proposed design approach, a field–circuit model of electromagnetic phenomena in the studied motor was developed and used to study the motor performance. The increased torque value and reduction in torque ripples were confirmed by comparison to the classical three-phase SynRM design. To illustrate fault tolerance capabilities, the operation of the studied three- and six-phase synchronous reluctance motors under inverter-fault conditions was examined. The conducted analysis shows, among other things, that from the electromagnetic performance point of view, only the proposed six-phase machine is able to properly operate under inverter-fault conditions. The results of the winding design calculations, the performed simulations of six-phase motor operation, and the preliminary tests of the prototype motor are presented and discussed. [ABSTRACT FROM AUTHOR]

The inverter dead time effect is non-negligible for the control performance of sensorless synchronous reluctance motor (SynRM) drives at low speeds. In this paper, a reduced-order observer-based sensorless control method for SynRM drives combined with the adaptive linear neurons (ADALINE)-based dead-time compensation is proposed. The reduced-order observer-based sensorless control method is presented, for which is parameter tuning is easy. On this basis, the dead-time compensation strategy using ADALINE filters is proposed to reduce the voltage harmonics effect on the estimation performance of the reduced-order observer. With ADALINE filters, the sixth current harmonic can be successfully filtered out by compensating the voltage directly or fitting the current to compensate the voltage. In this way, the low-speed estimation performance of the reduced-order observer is improved. The effectiveness of the proposed method is verified on a 3 kW SynRM experimental platform. [ABSTRACT FROM AUTHOR]

Aiming at the influence of eccentric faults on the performance of synchronous reluctance motor (SynRM), the distribution characteristics and change rules of dynamic electromagnetic stress before and after eccentric faults of SynRM were studied. A dynamic electromagnetic stress calculation model combining eccentric fault finite element method and Maxwell tensor method is established under the influence of magnetic saturation. The dynamic electromagnetic stress before and after the eccentric fault of the rotor surface, rotor magnetic ribs, and stator tooth wall are calculated, and the differences in the electromagnetic stress distribution are analyzed in detail. The analysis methods and results of electromagnetic stress provide a reference for the design and structure optimization of SynRM, and it also presents a theoretical guarantee for the smooth and orderly operation of SynRM. [ABSTRACT FROM AUTHOR]

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study introduces a novel approach to enhance state and unknown input estimation for the synchronous reluctance motor, utilizing the Takagi-Sugeno fuzzy representation. A proportional multi-integral observer structure is introduced, capable of capturing a wider range of unknown input dynamics compared to the previous proportional integral observer utilized in prior research. Stability conditions, obtained using the quadratic Lyapunov function, are formulated as linear matrix inequalities to guarantee the asymptotic convergence of the estimation error. To evaluate the effectiveness of the proposed observer, different cases were considered, including scenarios with slow and fast variations of the unknown input. Through hardware-in-the-loop validation, the results clearly demonstrate the superiority of the proposed method over the earlier approach. This advancement signifies a significant improvement in the estimation accuracy and reliability of the Synchronous Reluctance Motor.

There are usually noise problems when the position sensorless control of a synchronous reluctance motor (SynRM) is carried out by high-frequency (HF) signal injection method. Due to the special structure, the cross-saturation effect of the SynRM is particularly serious, resulting in reduced position observation accuracy. In this paper, a variable-angle random HF voltage injection strategy with cross-saturation effect compensation is proposed for position sensorless SynRM drives. Random number generation based on the chaotic mapping method is used to generate random HF voltage signals with different frequencies for injection; the current power spectral density (PSD) distribution is extended and the HF noise can be reduced. A control strategy based on variable-angle square-wave injection is proposed to suppress the cross-saturation effect. By measuring the position error curves of different loads off-line and polynomial fitting the curves, the position error is achieved by combining with the corresponding signal demodulation algorithm. The proposed method does not require additional hardware resources and can maintain high control accuracy and robustness. Finally, the effectiveness of the proposed sensorless control strategy is verified on a 3 kW SynRM experimental platform. [ABSTRACT FROM AUTHOR]

There is significant practical and scientific interest in synchronous reluctance motors with a transversally laminated anisotropic (TLA) rotor. TLA rotor core has a transverse lamination, internal grooves and highly saturated areas. The configuration of rotor slots is complex and varied. It is an urgent task to develop a parametric model of a synchronous reluctance motor with a TLA rotor designed to calculate steady-state and transient engine operating conditions. A classical parametric model of a synchronous reluctance motor is used that is based on the theory of two reactions. The presented method for calculating the parameters of a model of a synchronous reluctance motor with a TLA rotor is based on the results of a field calculation of two static states of a magnetic field. Calculations of steady-state conditions of a synchronous reluctance motor are performed according to engineering formulas, which are obtained from the equation of voltage equilibrium in the stator phase. To calculate the transient modes of a synchronous reluctance motor, the Park—Gorev equations were used. Field models of the synchronous reluctance motor under study are presented for axial and transverse rotor positions. The magnetic field's main harmonics in the gap and their dependences on the armature current are calculated. Formulas are given for calculating the armature winding inductive parameters and a synchronous reluctance motor operating characteristics. Differential equations used to calculate processes in a synchronous reluctance motor are presented. Using a parametric model, the operating characteristics of a synchronous reluctance motor, the process of frequency starting, and the electromechanical process of a synchronous reluctance motor's operation with an asymmetrical power supply are calculated. Calculation results are compared with the field modeling results of a synchronous reluctance motor with a TLA rotor in the Ansys Maxwell environment. The classical parametric model of a synchronous machine based on the theory of two reactions allows one to quickly and accurately analyze the steady-state and transient operating conditions of a synchronous reluctance motor with a TLA rotor under various power and mechanical load conditions, including abnormal ones. [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]

This study presents an enhanced AC drive for the SynRMs coupled with a circulation pump (CP) and an improved control system based on the field orientation. A grid-fed 900 W motor driver consisting of an electromagnetic interference filter (EMI), power factor correction (PFC), and three-phase inverter is designed to drive 0.75 kW SynRM. A boost PFC converter is designed as an interface between the AC power line and the motor drive. PFC is used to recover the bad power factor performance of the SynRM. In addition, the boosted and well-regulated DC-link voltage improves the motor driving performance. Control strategies and practical implementation based on the field-oriented control of synchronous reluctance motors are presented. Dynamic and steady-state responses of the CP SynRM drive in various conditions are verified experimentally. Low current and voltage ripples, unity power factor, maximum torque per ampere with low fluctuation and low EMI noise are achieved with the low cost efficiently. All of the improvements are obtained by fewer circuit elements and higher energy conversion efficiency. The advantages of using SynRMs in dry-rotor circulation pumps for heating applications have been demonstrated experimentally. [ABSTRACT FROM AUTHOR]

In recent years, studies aiming to use different motor types for traction purpose, such as in electric vehicles, have become increasingly widespread. Among these motor types, permanent magnet assisted synchronous reluctance motor has become increasingly preferred in commercially electric vehicles nowadays. This study addresses the design and control of a permanent magnet assisted synchronous reluctance motor, also the comparison with the synchronous reluctance motor. The motor design process is carried out using the finite element method in Ansys-Maxwell environment. A series of a simulation studies is conducted in the MATLAB/Simulink environment for controlling the obtained motor designed in Ansys-Maxwell. The field-oriented control approach is chosen for precise speed control. As a result of the simulation studies, it is observed that the designed motor tracks the reference with minimal error under various load conditions within a closed-loop system Also, this paper investigates how the permanent magnet implementation affects the machine performance comparing to synchronous reluctance motors. In addition, such a study takes into account that the design of machines involves always several constraints, including geometry, materials, supply limits, and performance constraints. [ABSTRACT FROM AUTHOR]

Smart, Micro and Nano-grids are the future of electric power systems. In parallel with this future, electric vehicles (EVs) take a great deal of attention, as they are one of the important elements in these systems. Also, with the passage of time, the development continues in the technology of manufacturing EVs. Since the electric motor is the main component in these vehicles, research and development is continuing to find the most suitable motors that can work in such vehicles. The synchronous reluctance motor (SynRM) is the newest motor used in this industry. SynRMs faces different challenges, one of which is the torque ripples. Different trials were used to reduce or eliminate or minimize these ripples. Most of previous work focuses on the SynRM design parameters to reduce torque ripples. In this paper, the control methodology and the strong action controller (SAC) are used as a tool to reduce these ripples. The simulation results showed the effectiveness of the application of the proposed SAC in ripples factor reduction. This reduction represents a new contribution over the already existed techniques.

In this study, a novel composite speed controller combining a sliding-mode speed controller with a disturbance observer is proposed for the vector-controlled synchronous reluctance motor (SynRM) drive system. The proposed composite speed controller employs the generalized super-twisting sliding-mode (GSTSM) algorithm to construct both the speed controller and the disturbance observer. The GSTSM speed controller is utilized to stabilize the speed tracking error dynamics in finite time, while the GSTSM disturbance observer compensates for the total disturbance in the speed tracking error dynamics, which includes external disturbances and parametric uncertainties. Under the framework of the constant direct-axis current component vector control strategy for the SynRM drive system, comparative simulation studies are conducted among the standard STSM speed controller, the GSTSM speed controller, the composite speed controller using a GSTSM speed controller and a standard STSM disturbance observer, and the proposed composite speed controller. The effectiveness and superiority of the proposed composite speed controller are verified through simulation results.

This paper contains research on the development of a fault-tolerant six-phase synchronous reluctance motor (SynRM) based on the stator adopted from a general-purpose three-phase induction motor. In the design and calculation process, an extended Clarke transformation was developed for a six-phase asymmetrical system. To verify the proposed design approach, a field–circuit model of electromagnetic phenomena in the studied motor was developed and used to study the motor performance. The increased torque value and reduction in torque ripples were confirmed by comparison to the classical three-phase SynRM design. To illustrate fault tolerance capabilities, the operation of the studied three- and six-phase synchronous reluctance motors under inverter-fault conditions was examined. The conducted analysis shows, among other things, that from the electromagnetic performance point of view, only the proposed six-phase machine is able to properly operate under inverter-fault conditions. The results of the winding design calculations, the performed simulations of six-phase motor operation, and the preliminary tests of the prototype motor are presented and discussed.

The inverter dead time effect is non-negligible for the control performance of sensorless synchronous reluctance motor (SynRM) drives at low speeds. In this paper, a reduced-order observer-based sensorless control method for SynRM drives combined with the adaptive linear neurons (ADALINE)-based dead-time compensation is proposed. The reduced-order observer-based sensorless control method is presented, for which is parameter tuning is easy. On this basis, the dead-time compensation strategy using ADALINE filters is proposed to reduce the voltage harmonics effect on the estimation performance of the reduced-order observer. With ADALINE filters, the sixth current harmonic can be successfully filtered out by compensating the voltage directly or fitting the current to compensate the voltage. In this way, the low-speed estimation performance of the reduced-order observer is improved. The effectiveness of the proposed method is verified on a 3 kW SynRM experimental platform.

The design and analysis of synchronous reluctance motor (SynRM) with a distributed type winding is an alternative to replace the permanent magnet synchronous motors (PMSM), which is commonly used in electric vehicle applications. The use of a SynRM eliminates the need for permanent magnets (PMs), reducing the dependence on rare earth materials and potentially lowering costs. In this paper, there are two approaches: a new approach of step-skewing rotor (SSR) is proposed to improve eletromagnetic parameters such as minimization of the active volume, maximization of the output power and reduction of the torque ripple of the SynRM. Then, a finite element technique is developed to analyse and simulate the distribution of magnetic flux and map efficiency of the proposed SynRM. Additionally, the paper has also investigated the distribution of temparature and machnical stress in the region of flux barries of the rotor.

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study proposes the SIMP-based topology optimization which can design a high-torque synchronous reluctance motor (SynRM) in an efficient way. Although it is crucial to simultaneously optimize a SynRM design and the corresponding current-phase angle for the maximum performance, most studies to date have conducted design optimization at a fixed current-phase angle for simplicity. It is also difficult to consider the magnetic nonlinearity and complicated design features in topology optimization. To solve the above issue, this study expresses the optimal current-phase angle (β(MTPA)) for the SynRM as a function of design variables (ρ). To efficiently determine β(MTPA)(ρ), the average torque curve is interpolated by using the modified Akima method. For interpolation, three-time electromagnetic finite element (FE) analyses are conducted at every iteration. The structural FE analysis is also performed at every iteration to obtain a structurally meaningful design. Through the above procedure, the SynRM design and the corresponding current excitation can be simultaneously optimized. Optimization results are discussed in terms of computational accuracy and efficiency, compared with other methods. [ABSTRACT FROM AUTHOR]

Fault diagnosis and condition monitoring of synchronous machines running under load is a key determinant of their lifespan and performance. Faults such as broken rotor bars, bent shafts and bearing issues lead to eccentricity faults. These faults if not monitored may lead to repair, replacement and unforeseen loss of income. Researchers who attempted to investigate this kind of machine stopped at characterizing and deduced ways, types and effects of rotor eccentricity fault on the machine inductances using the winding function method. A modified closed-form analytical model of an eccentric synchronus reluctance motor (SynRM) is developed here taking into cognizance the machine dimensions and winding distribution for the cases of a healthy and unhealthy SynRM. This paper reports the study the SynRM under static rotor eccentricity using the developed analytical model and firming up the model with finite element method (FEM) solutions. These methods are beneficial as they investigated and presented the influence of the degrees of static eccentricity on the machine performance indicators such as speed, torque and the stator current and assess the extent to which the machine performance will deteriorate when running with and without load. The results show that static eccentricity significantly affects the machine's performance as the degree of eccentricity increases. [ABSTRACT FROM AUTHOR]

Background and Objectives: The rotor of synchronous reluctance machines (SynRM) is conventionally designed and implemented in two types of axiallylaminated anisotropic (ALA) and transversely-laminated anisotropic (TLA). Torque ripple and power factor have always been the design challenges of this machine; however, with proper design, their values can be as close as possible to the desired value. Each of these two structures has some advantages over the other, in terms of electromagnetic performance and ease of construction. For the first time, in this paper, a hybrid anisotropic rotor is presented with both radial and axial laminations, based on the theory of anisotropic rotor structure for the fundamental harmonic and isotropic rotor structure for other harmonics, so that the designed motor meets the advantages of both structures as much as possible. Methods: To this end, the proposed design is implemented and investigated a Magnetic Equivalent Circuit (MEC) for the first slot harmonic on a machine with stator of 24-slots. To evaluate the proposed design, its electromagnetic performance is simulated using Finite Element Method. Results: The theory-based conceptual design method is applied to a rotor with new structure and simulation results including average torque, power factor and torque ripple of the machine are presented. Conclusion: Based on the obtained simulation results and comparing performance of the proposed design with other structures, it is shown that there will be a significant improvement in electromagnetic features including torque ripple, average torque and power factor and the proposed design has lower torque ripple than ALA rotor and higher average torque and power factor than TLA rotor. [ABSTRACT FROM AUTHOR]

Air-conditioners are now widely being used in offices and domestic homes due to the rising global temperatures. Inverter-driven air-conditioners offer superior cooling performance, enhanced control, and a more compact design than non-inverter-driven air-conditioners. Further, inverter-driven air conditioners are more efficient and also cost-effective within a pay-back period. Nowadays, efficient motor drives that meet international efficiency (IE) standards are the need of the hour. Permanent magnet-assisted reluctance motor (PMa-SyRM) drives are one such feasible solution for air conditioner applications, where very less magnet volume is used thereby improving the efficiency whilst minimizing the overall cost. This paper presents a variable-speed rare-earth-free ferrite Al-Ni-Co hybrid PMa-SyRM drive for an air conditioner application. Hall-sensors are used for detection of the rotor position and a simple current advance angle based control is implemented to extract both the magnetic and reluctance torque components from the hybrid PMa-SyRM. Later, simulation studies are carried-out and the cost and the efficacy of the proposed control is compared with that of the conventional maximum torque per ampere (MTPA) control. Finally, a prototype drive is fabricated and experimental validation under various load conditions is carried-out and the results are presented.

Three-phase Induction Motors (TPIM) are popular in industrial applications due to their numerous advantages. However, TPIM has comparatively lower efficiency than modern motor technologies like permanent magnet synchronous motor(PMSM), synchronous reluctance motor(SynRM), or switched reluctance motor(SRM). The expensive rare earth material and the inability of line starting operation discourage the replacement of TPIM with these modern energy-efficient motors. This research proposes a novel conversion of TPIM into Line Start SynRM (LS-SynRM) to cause a cost-effective and compatible performance solution. The proposed design modifications are carried out on the existing 0.5HP, TPIM rotor and analyzed using finite element (FE) software. The optimum barrier parameters such as barrier end width, barrier position, barrier width, and rib width have been determined through parametric analysis. The considerable effect of barrier dimensions on motor performance is evident from the analysis.

There are usually noise problems when the position sensorless control of a synchronous reluctance motor (SynRM) is carried out by high-frequency (HF) signal injection method. Due to the special structure, the cross-saturation effect of the SynRM is particularly serious, resulting in reduced position observation accuracy. In this paper, a variable-angle random HF voltage injection strategy with cross-saturation effect compensation is proposed for position sensorless SynRM drives. Random number generation based on the chaotic mapping method is used to generate random HF voltage signals with different frequencies for injection; the current power spectral density (PSD) distribution is extended and the HF noise can be reduced. A control strategy based on variable-angle square-wave injection is proposed to suppress the cross-saturation effect. By measuring the position error curves of different loads off-line and polynomial fitting the curves, the position error is achieved by combining with the corresponding signal demodulation algorithm. The proposed method does not require additional hardware resources and can maintain high control accuracy and robustness. Finally, the effectiveness of the proposed sensorless control strategy is verified on a 3 kW SynRM experimental platform.

Fault diagnosis and condition monitoring of synchronous machines running under load is a key determinant of their lifespan and performance. Faults such as broken rotor bars, bent shafts and bearing issues lead to eccentricity faults. These faults if not monitored may lead to repair, replacement and unforeseen loss of income. Researchers who attempted to investigate this kind of machine stopped at characterizing and deduced ways, types and effects of rotor eccentricity fault on the machine inductances using the winding function method. A modified closed-form analytical model of an eccentric synchronus reluctance motor (SynRM) is developed here taking into cognizance the machine dimensions and winding distribution for the cases of a healthy and unhealthy SynRM. This paper reports the study the SynRM under static rotor eccentricity using the developed analytical model and firming up the model with finite element method (FEM) solutions. These methods are beneficial as they investigated and presented the influence of the degrees of static eccentricity on the machine performance indicators such as speed, torque and the stator current and assess the extent to which the machine performance will deteriorate when running with and without load. The results show that static eccentricity significantly affects the machine’s performance as the degree of eccentricity increases.

The synchronous reluctance motor (SynRM) has significant nonlinear characteristics due to the problems of magnetic saturation and cross-coupling and the poor adaptability of the general controller to parameter changes seriously affects the control performance of the motor. In order to solve the above problems, this paper proposed a control system for the SynRM with a brain emotion controller based on empirical information to solve the motor control problem of magnetic saturation. Firstly, the nonlinear mathematical model of the SynRM considering magnetic saturation is established by introducing the magnetic saturation parameter. Secondly, the sensory input function and emotional cue function based on systematic error are given and the vector control system of the SynRM considering magnetic saturation is designed. The influence of the parameters and the learning rate of the brain emotional learning based intelligent controller (EI-BELBIC) on the adjustment range of the controller parameters is studied. Then the SynRM is controlled under different working conditions and the control effect is observed. The results show that the designed vector control system of the SynRM based on EI-BELBIC has strong reliability, accurate control, rapid response, and strong anti-interference ability under magnetic saturation. [ABSTRACT FROM AUTHOR]

This paper presents an evolutional topology optimization of electric machines, which works like gradient‐based local search methods, based on the covariance matrix adaptation evolution strategy (CMA‐ES). The present method enables to improve the performance of initial machine shapes without computing the deviation of the objectives. Moreover, for the resultant shapes obtained by the present topology optimization method, this paper also presents a sensitivity analysis method based on the normal distribution which is used to seek for solutions in CMA‐ES. Using the present sensitivity analysis method, important parts which contribute to improve a machine characteristic can be visualized. The two present methods are applied to the optimization problem of a synchronous reluctance motor. It is shown that initial rotor shapes defined by designers can effectively be modified using the present optimization method. Moreover, it is also shown that the sensitivity distributions with respect to some machine characteristics are visualized by the present method. In addition, each machine characteristic is respectively improved by modifying the machine shape according to the respective sensitivities. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

This article proposes a novel method to reduce rotor movement when estimating magnetic flux models for interior permanent magnet synchronous motors (IPMSMs) and synchronous reluctance motors (SynRMs). A rotation reduction technique that considers the flux saturation effect is proposed. A hysteresis controller is used to inject voltages only into the q-axis and simultaneously into the dq-axes. The rotation of the IPMSM is reduced by calculating the current at the point where the integral of the q-axis current over time becomes zero. In the case of SynRM, the rotation is reduced by calculating the injection voltage magnitudes such that the oscillation frequency of the q-axis current is higher than that of the d-axis current. The effectiveness of the proposed method was experimentally demonstrated using an 11-kW IPMSM and 1.5-kW SynRM. The proposed technique can be used for the self-commissioning of IPMSMs and SynRMs at a standstill, without rotor locking, or position sensors. [ABSTRACT FROM AUTHOR]

In this paper, we design a proportional integral observe for a nonlinear synchronous reluctance motor described by a Takagi–Sugeno multi-model. In this design, both states and unknown inputs are estimated simultaneously. First, the mathematical nonlinear model of the synchronous reluctance motor is established, then it transformed into a Takagi–Sugeno exact form by a simple polytopic transformation. In The second step, the proposed observer is designed to the obtained fuzzy system. Convergence conditions are expressed under a linear matrix inequality formulation using the second Lyapunov theorem, which guarantee a bounded error. Observer gains are obtained by solving a sum of constraints. For validation purposes, a hardware-in-the-loop implementation were carried out leading to results that clearly demonstrate the performance and effectiveness of the proposed technique. • Unknown input observer is designed for a non linear systems via Takagi–Sugeno (TS) fuzzy model. • TS fuzzy model, is obtained by using the non linear sector transformation. • Stability of the TS fuzzy model is guaranteed via a quadratic function of Lyapunov. • Observer gains can be obtained by solving a set of linear matrix inequalities using Matlab/YALMIP toolbox. • The effectiveness and feasibility of the proposed observer has been validated via a hardware in the loop platform. [ABSTRACT FROM AUTHOR]

In this study, design, optimization, and performance improvement of a 2-kW synchronous reluctance motor (SynRM) have been performed for micro-mobility electric vehicles. The finite-element method has been used for analyses. At first, SynRM has been designed in Ansys Maxwell with initial stator and rotor parameters. Then, stator and rotor parameters of SynRM have been optimized by using a genetic algorithm. Thus, the torque capacity of SynRM has been increased and the torque ripple has been reduced. In addition, the performance of optimized SynRM has been investigated by adding magnets to its rotor. Designed SynRM and permanent magnet-supported SynRM have been compared. It has been seen that the permanent magnet-supported SynRM produces higher torque with higher efficiency and less torque ripple. Simulation results proved that the permanent magnet-supported SynRM can be used successfully in micro-mobility class electric vehicles. [ABSTRACT FROM AUTHOR]

The goal of this article is to develop a new topology optimization framework that can secure the manufacturability of the synchronous reluctance motors (SynRMs) with multiple iron webs and bridges while satisfying the required electromagnetic and mechanical performances. In the SynRM, multiple iron webs and bridges are crucial to achieve a higher torque and a structural safety. A minimum thickness of the web and bridge should also be guaranteed to achieve manufacturability. To acquire the optimal SynRM that can satisfy the above characteristics, a two-stage topology optimization framework is proposed with an individual filtering-and-penalization scheme. This proposed scheme can individually control the number and thickness of multiple iron webs and bridges in the rotor to obtain the manufacturable and structurally safe SynRMs. For the abovementioned purpose, topology optimization is formulated to minimize a torque ripple while satisfying the desired average torque, structural compliance, and a rotational moment of inertia. Average torque and structural compliance are evaluated by performing the electromagnetic and structural finite element analyses, respectively, at each iteration of topology optimization. Here, design-dependent loads are considered in the radial and circumferential directions to reflect a high-speed rotation. Through investigating the optimized SynRM designs with various filter radii, the relationship among the torque, structural pattern, and stress distribution is examined. Finally, the experimental results with the manufactured prototypes validate the feasibility and potential of the proposed design method. [ABSTRACT FROM AUTHOR]

A Model-based predictive current control (MBPCC) has recently become a powerful advanced control technology in industrial drives. However, MBPCC relies on the knowledge of the system model and parameters, being, therefore, very sensitive to parameters errors. In the case of the synchronous reluctance motor (SynRM), where the parameters vary due to its ferromagnetic structure and nonlinear magnetic properties, MBPCC performance would suffer significantly. Accordingly, in this paper, a Grey Wolf Optimizer based model-free predictive current control (GW-MFPCC) of SynRM is proposed, to skip all the effects of the model dependency and parameters uncertainty. The proposed method predicts the stator current through tracking the minimum cost function using the grey wolf optimizer. The proposed GW-MFPCC scheme is compared to MBPCC, and its effectiveness is evaluated and confirmed by experimental results. [ABSTRACT FROM AUTHOR]

Recently, model-based predictive current control (MB-PCC) has been presented as a good alternative to classical control algorithms in terms of simplicity and performance reliability. However, MB-PCC suffers from the high dependence on system parameters, which may deteriorate its performance under parameters variations. On the other hand, synchronous reluctance motors (SynRMs) are susceptible to suffer from inductances variations due to the magnetic saturation. Accordingly, in this article a new model-free predictive current control of SynRMs based on a recurrent neural network (RNN-PCC) is developed and proposed. The proposed RNN-PCC relies on the identification of the SynRM currents without considering any parameters. Simulation and experimental results show that both RNN-PCC and MB-PCC have similarly excellent dynamics, while better control performance and tracking errors can be achieved thanks to the proposed RNN-PCC. [ABSTRACT FROM AUTHOR]

In this work, a proposed high-efficiency and low-cost photovoltaic water-pumping system based on semitransparent dye-sensitized solar cells (DSSCs) is presented. DSSCs are low-cost third-generation photovoltaics that have gained a lot of interest as a promising alternative for silicon solar cells. DSSCs are fabricated at low cost and low temperature and present power conversions with high efficiency, exceeding 14%, thanks to high transparency, a variety of colors, and high efficiency, even in low light conditions. The DSSC modules used in this study were tested under different working conditions, and their characteristics were determined experimentally and simulated theoretically via MATLAB. A complete laboratory infrastructure is constructed to test the proposed photovoltaic water-pumping system based on the DSSC module array. The system contains a synchronous reluctance motor driving a water pump and feeding from the DSSCs via an inverter without DC–DC converters or batteries. The proposed system has many merits, such as high efficiency and low cost. The DSSCs' maximum available power is obtained via a maximum power point tracking technique (perturb-and-observe). Moreover, a control system for driving the motor via the inverter was also implemented. The maximum torque per ampere strategy is also considered in the proposed control system to drive the motor efficiently using the inverter. Finally, experimental validation of the complete system via laboratory measurements is implemented. [ABSTRACT FROM AUTHOR]

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