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The sensorless control of synchronous reluctance motor (SynRM) in the zero and low‐speed domain using the traditional high‐frequency injection method has the problems of audible noise caused by the high‐frequency injection and high‐frequency loss caused by the change of working conditions, which limits the practical application of SynRM in the industrial field. To solve the problem of high‐frequency noise and loss, a pseudo‐random high‐frequency injection method considering parameter variation is proposed in this paper. Firstly, the signal injection form was adjusted to expand the power spectral density of the high‐frequency current, and the current energy spike was suppressed to reduce high‐frequency noise. Secondly, the current demodulation was combined with the flux map model to complete the injection voltage amplitude adjustment, so that the response current was kept constant under multiple operating conditions to reduce the high‐frequency loss. At the same time, the flux map model is applied to the observer to reduce the rotor position estimation error caused by the cross‐coupling effect. Under the condition of satisfying the dynamic and steady performance requirements of sensorless control, the high‐frequency loss and sharp noise caused by the high‐frequency injection method are effectively suppressed. Finally, experiments were carried out on a 1.5 kW SynRM drive platform to verify the feasibility and effectiveness of the sensorless control scheme in this paper. [ABSTRACT FROM AUTHOR]

Outdated, oversized variable speed pump drives (VSDPs) in industry lead to sub-optimal energy efficiency and considerable energy losses. This paper proposes methods to develop 2D efficiency maps for motors, converters, and pumps using polynomial surface fitting, which enables efficiency evaluation in a wide operating range. The method was applied to an oversized VSDP in an industrial chilled water supply system, comparing the original system with five alternative VSDP combinations with high-efficiency motors and pumps. The five VSDP variants demonstrated average energy savings of around 30%, with the synchronous reluctance motor (SRM) configurations outperforming the induction motor (IM) configurations by up to 7 percentage points, particularly at low loads. The high-efficiency SRM-based 252-IE5 variant delivered the best overall energy performance, highlighting the benefits of optimised system sizing and motor selection for energy savings. The proposed method can be used in both industrial and residential applications and offers great advantages in process systems that require variable flow and pressure of water or other fluids during operation, such as HVAC, water supply and wastewater treatment, district heating, etc. The development of a VSDP drive with efficient energy optimisation is an interdisciplinary problem of mechanical and electrical engineering, and without the interaction of engineers from both fields the result will not be optimal. We try to present our method so that it can be a reliable tool for mechanical, electrical, and other engineers or researchers to assist them in finding possible energy savings, performing energy audits, and selecting the most suitable components when modernising existing or developing new systems. [ABSTRACT FROM AUTHOR]

Synchronous reluctance motor has recently attracted the attention of researchers due to their characteristics such as higher efficiency compared to induction motors, lower cost in contrast to permanent magnet motors, robust rotor structure and limited rotor inertia. Also, research on five‐phase motors, which have more reliability and torque density than three‐phase motors, is of a great importance. In this essay, the optimization of the robust design of a five‐phase reluctance synchronous motor has been done through the design of experiments using the sequential Taguchi method based on fuzzy logic. To ensure that the performance of the motor is not sensitive to changes and uncertainties, the air gap manufacturing tolerances, the width of the rotor's tangential rib and the rotor's pitch control angle are considered as noise factors. In addition, to improve the motor's fault tolerance capacity, the main performance characteristics of the motor under single‐phase fault operation, such as average torque and ripple torque are considered as optimization targets, along with the main performance characteristics of the motor under normal operation. By comparing the optimization results of the proposed method with the conventional Taguchi optimization method, the effectiveness and superiority of the proposed method have been confirmed. [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.

The mechanical strength of the synchronous reluctance motor (SynRM) has always been a great challenge. This paper presents an analysis method for assessing stress equivalence and magnetic bridge stress interaction, along with a multiobjective optimization approach. Considering the complex flux barrier structure and inevitable stress concentration at the bridge, the finite element model suitable for SynRM is established. Initially, a neural network structure with two inputs, one output, and three layers is established. Continuous functions are constructed to enhance accuracy. Additionally, the equivalent stress can be converted into a contour distribution of a three-dimensional stress graph. The contour line distribution illustrates the matching scheme for magnetic bridge lengths under equivalent stress. Moreover, the paper explores the analysis of magnetic bridge interaction stress. The optimization levels corresponding to the length of each magnetic bridge are defined, and each level is analyzed by the finite element method. The Taguchi method is used to determine the specific gravity of the stress source on each magnetic bridge. Based on this, a multiobjective optimization employing the Multiobjective Particle Swarm Optimization (MOPSO) technique is introduced. By taking the rotor magnetic bridge as the design parameter, ten optimization objectives including air-gap flux density, sinusoidal property, average torque, torque ripple, and mechanical stress are optimized. The relationship between the optimization objectives and the design parameters can be obtained based on the response surface method (RSM) to avoid too many experimental samples. The optimized model is compared with the initial model, and the optimized effect is verified. Finally, the temperature distribution of under rated working conditions is analyzed, providing support for addressing thermal stress as mentioned earlier.

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]

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]

This study focuses on the maximum torque current ratio control of synchronous reluctance motors and proposes an optimized control method for the maximum torque current ratio of synchronous reluctance motors based on virtual signal injection. Firstly, the research on the maximum torque current ratio control of synchronous reluctance motors based on the virtual signal injection method is conducted, and the existing virtual unipolar square wave signal injection method is analyzed and studied. Secondly, a non-parametric maximum torque current ratio control strategy based on a synchronous reluctance motor combined with the virtual signal injection method is proposed. This strategy does not involve complex parameter calculations, and the control accuracy is not limited by the accuracy of the parameters in the model. The experimental results showed that under the control of virtual bipolar and unipolar square wave signal injection methods, the load torque was converted from 2 Nm to 6 Nm at t = 2:5 s, and there was a significant change in the current amplitude and waveform of the current vector. Under the control of the bipolar injection method, the current amplitude waveform of the motor was lower than that of the unipolar waveform, and the current was smaller. After the load suddenly changed, it could enter a stable state faster. After the load changed at t = 2:5 s, the phase angle of the current vector was quickly adjusted and stabilized under the control of the bipolar signal. The designed method has a good optimization effect compared to the traditional virtual signal injection method, and can achieve high-performance maximum torque current ratio optimization control on synchronous reluctance motors. [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.

In pursuit of improving energy efficiency in the industry, this paper proposes two model-based loss-minimization techniques for synchronous reluctance motors (SynRM): the model-based loss-minimization robust method (MLR) and the simplified model-based loss-minimization robust method (SMLR). Both techniques belong to the broader category of model-based methods, which are known for their fast dynamic convergence, low torque ripple, and reduced computational load compared to search-based and hybrid methods. Results reveal that both MLR and SMLR exhibit appropriate performance against motor parameter variations, particularly in the components of stator inductance ( $L_{dq}$ ), while maintaining high efficiency and minimal power loss. The study paves the way for the integration of these techniques into control strategies that use active flux to further enhance the efficiency of SynRM in industrial applications. The paper presents a comprehensive and thorough sensitivity analysis, along with detailed experimental results, that effectively verify the proper and consistent performance of the proposed methods across various operating points.

Outdated, oversized variable speed pump drives (VSDPs) in industry lead to sub-optimal energy efficiency and considerable energy losses. This paper proposes methods to develop 2D efficiency maps for motors, converters, and pumps using polynomial surface fitting, which enables efficiency evaluation in a wide operating range. The method was applied to an oversized VSDP in an industrial chilled water supply system, comparing the original system with five alternative VSDP combinations with high-efficiency motors and pumps. The five VSDP variants demonstrated average energy savings of around 30%, with the synchronous reluctance motor (SRM) configurations outperforming the induction motor (IM) configurations by up to 7 percentage points, particularly at low loads. The high-efficiency SRM-based 252-IE5 variant delivered the best overall energy performance, highlighting the benefits of optimised system sizing and motor selection for energy savings. The proposed method can be used in both industrial and residential applications and offers great advantages in process systems that require variable flow and pressure of water or other fluids during operation, such as HVAC, water supply and wastewater treatment, district heating, etc. The development of a VSDP drive with efficient energy optimisation is an interdisciplinary problem of mechanical and electrical engineering, and without the interaction of engineers from both fields the result will not be optimal. We try to present our method so that it can be a reliable tool for mechanical, electrical, and other engineers or researchers to assist them in finding possible energy savings, performing energy audits, and selecting the most suitable components when modernising existing or developing new systems.

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]

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.

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.

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.

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]

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.

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.

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]

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 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]

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]