Design Of Synchronous Reluctance Motor Research Articles

Torque ripples reduction of electric vehicle synchronous reluctance motor drive using the strong action controller

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.

A Modified Permanent Magnet-Assisted Synchronous Reluctance Motor Design for Torque Characteristics Improvement

A modified configuration for Permanent Magnet Assisted Synchronous Reluctance Motors (PMaSyRM) is studied in this paper. Conventionally, the PM materials are inserted in the flux barriers region of the rotor. Consequently, the PMs sizing parameters will be restricted to the available space that may limit the efficient use of PMs benefits. In this study, a portion of the rotor structure is replaced with an Interior PM (IPM) rotor so that an axially segmented integration of IPM and SyRM is obtained. Thus, the PMs design is performed specifically in the IPM segment independent of the SyRM scheme, while the SyRM segment remains PM-less. The main motivation of this concept is to improve the contribution of the PM material in the total torque as well as utilizing the special property of the proposed rotor configuration for pulsating torque reduction. A computationally cost-effective algorithm is proposed for the optimal design of IPM-SyRM motor by which a low-power design is carried out for a lightweight electric vehicle. The results for torque profile characteristics, PM volume, power-factor, and efficiency are compared with a conventional PMaSyRM that has been optimally designed as the reference case. Finally, a prototype is constructed to verify the theoretical analysis.

Shape optimization of synchronous reluctance motor using sensitivity information for multiple objective functions

PurposeThis paper aims to further improve the efficiency of multi-objective optimization design of synchronous reluctance motors (SynRMs) using the level set (LS) method, which has the advantage of obtaining a practical shape. The solutions obtained by gradient methods tend to be local ones due to the multi-modality of the objective function, especially when multiple objective functions. A huge number of trial calculations are required to obtain a high-quality and broadly distributed Pareto front. Therefore, it is indispensable to effectively get out of the local solutions in the optimization process with the LS method.Design/methodology/approachThe authors propose a novel method appropriately switching multiple objective functions with high independence of sensitivity information. The authors adopt highly independent mathematical expressions for the objective functions of the average torque and torque ripple. In addition, the authors repeatedly perform the optimization while appropriately selecting the sensitivity information of one objective function from multiple ones, which enables the authors to effectively break out of local solutions in the optimization process.FindingsThe proposed method was applied to the shape optimization of SynRM flux barriers and successfully searched a more extensive and advanced Pareto front in comparison with the conventional method.Originality/valueThe proposed method adopts search spaces with mathematical high independence for average torque and torque ripple. In the optimization process, when the solution search is judged to get stuck by several criteria, the search space is alternately switched to effectively get out of local solutions.

Topology Optimization Combined with a Parametric Algorithm for Industrial Synchronous Reluctance Motor Design

In this paper, we propose combining topology optimization with a parametric algorithm (TOCPA) to design an industrial synchronous reluctance motor (SynRM) that satisfies super-premium efficiency (IE4). TOCPA consists of two main processes. An improved niching algorithm is proposed as an existing parametric algorithm, and multiple optimal points were identified quickly and effectively within the design range specified by the user. Existing parametric algorithms lack the ability to find unpredictable new optimal shapes; therefore, topology optimization has been added. TOCPA converges the two optimization methods to compensate for the shortcomings of each and maximizes the advantages. In addition, the boundary surface ON–OFF method is applied to accelerate the topology optimization process. Subsequent ratio-based smoothing techniques smooth out discontinuous interfaces and remove clusters to improve the torque characteristics and reduce the manufacturing difficulty. Finally, the torque ripple was reduced using the skew technique, and mechanical stability was confirmed using a stress analysis. An IE4 industrial SynRM was successfully designed using TOCPA.

Optimal Design of a Synchronous Reluctance Motor Using a Genetic Topology Algorithm

The topology algorithm (TA) can effectively find an optimal solution by changing the material and shape of the design target without the limitation of design variables. In this paper, a genetic topology algorithm (GTA) is proposed for the design optimization of a synchronous reluctance motor (SynRM). By applying the stochastic algorithm (genetic algorithm (GA)) and the deterministic algorithm (ON-OFF method) to the design, the optimal shape can be found quickly and effectively. The GTA, which improves manufacturability by removing the aliasing that occurs in TA, was applied to the design of SynRM to search for the optimal model. After dividing the rotor into a reverse mesh grid, the optimal topology was searched for by GA and ON-OFF methods. Then, mechanical stability was verified through stress analysis, and additional performance improvement was obtained through the skew technique. The final design, which satisfies the minimum efficiency, required torque, and torque ripple was derived by applying the step-by-step design using GTA to the SynRM optimization.

Analytical Method to Optimum design of Synchronous Reluctance Motor for Electric Scooter Application

In recent years, synchronous reluctance motor (SynRM) has attracted the attention of researchers and well-known companies have been involved in designing and manufacturing electric motors due to its simplicity (no need for a rotor cage and permanent magnet), the similarity of its production line analogous to that of the induction motor, low production cost and also, compared to the induction motor, better performance, if optimally designed. Saliency ratio, defined as the ratio of the d axis inductance to the q axis inductance, is the most important parameter in designing a synchronous reluctance motor which has a major impact on achieving both maximum power factor and maximum torque. The current study aimed to provide a comprehensive approach to design a series of synchronous reluctance motors using both combined methods and finite element analysis to achieve an algorithm which is based on the similarity between flux lines and the shape of flux barriers to achieve both maximum torque and minimum torque ripple. The designed motor is intended to be used in an electric scooter application. Therefore, the geometrical dimensions of the motor, such as the motor stack outer diameter and length, are held constant in all cases.

Design and Experimental Evaluation of a 12 kW Large Synchronous Reluctance Motor and Control System for Elevator Traction

Recently, a new type of motor, synchronous reluctance motor (SRM), has attracted wide attention from academia and industry because of its potential applications in fans, pumps, and elevator traction systems. Compared with traditional motors, these motors have lower eddy-current loss, less torque ripple, reduced noise, smaller moment of inertia, and faster dynamic response, and they provide a greater operating efficiency and safety and are simpler and easier to maintain. However, the ontology design and operation control of SRMs continue to be significant hurdles that must be overcome prior to practical implementation. In order to facilitate the practical application of SRMs in industry, at the invitation of an elevator company, we designed a large SRM for elevator traction. Herein, we describe the design of the proposed system and present a theoretical analysis of the system. Furthermore, we fabricate a real prototype and the corresponding control system and perform an experimental test under the rated operating conditions and $1.5\times $ overload conditions in order to verify the SRM’s performance. The results of the experimental testing were satisfactory and consistent with the theoretical calculations. At present, we have entered the stage of small-batch trial production and we expect to ultimately implement this novel design. Further, the approach to ontology design and operation control in this study can be used to inform the future development of novel SRMs.

Powertrain EV synchronous reluctance motor design with redundant topology with novel control

A doubly three-phase fed synchronous reluctance machine (SynRM) is designed for electrical vehicle powertrain application. SynRM aims to deliver instant power and high power density, high torque at low speeds and high power at high speeds, wide speed range, high efficiency throughout its range of operation, ruggedness, high safety at a reasonable cost. Under these requirements, a 60 kW, 9000 rpm and 400 Nm SynRM has been designed. The main objective is to demonstrate the SynRM powertrain operation behaviour and determinate the operation points electrically and thermally. To reach the proposed SynRM goal, a new direct torque control algorithm based on output regulation subspace theory control is presented. The winding motor topology is galvanic isolated, so it is possible to operate with the six phases directly to the load and because of that, the combination with a back-to-back (B2B) converter becomes so profitable. To validate the system, two B2B full-converters and two motors (SynRM and induction machine) were used in a real test bench. Finally, a simulated and real efficiency map is obtained covering different drive cycles range. Some remarks about normal and failure mode of operation are presented.

Adaptive Particle Swarm Optimization Based on Kernel Support Vector Machine for Optimal Design of Synchronous Reluctance Motor

This paper proposes an adaptive particle swarm optimization (APSO) based on a kernel support vector machine (KSVM). The proposed algorithm improves the convergence speed and exploration capability of the APSO by employing an individual adaptive parameter control based on the KSVM. To verify the algorithm’s effectiveness, it was compared with both the conventional PSO and APSO based on test functions. Finally, we applied the proposed algorithm to the optimal design of a synchronous reluctance motor (Syn-RM).

3-D Structure Line-Start Synchronous Reluctance Motor Design Based on Selective Laser Melting of 3-D Printing

Due to the features of high efficiency, high torque, and without using permanent magnets, the synchronous reluctance motors (SynRMs) have become popular in industry. Such advantages are contributed by the design of the rotor barriers and ribs that the flux flow path are arranged as shown in Fig. 1(a). However, the requirements of motors usually are not just high efficiency but some other more operation capabilities such as low vibration and easy start. Unfortunately, as compared with the industrial most commonly used induction motors (IMs), position sensors are additionally required for initiating starting of SynRMs [1], [2]. Moreover, the barriers and ribs of SynRMs may increase the risk of structure deformation as rotation. Hence, this paper proposes a novel design of applying the 3D bionic structure in the SynRMs with new flux path design to solve the said problems. Further, the additive manufacturing (3D printing) is adopted to fabricate the complicated prototype of the rotor.

A Study on the Synchronous Reluctance Motor Design for High Torque by Using RSM

Recently, electric power consumption has increased rapidly owing to the development of electric devices, and thus environmental problems such as global warming have come to the fore. Therefore, developed and developing countries are preparing various measures to prevent global warming. Minimum energy performance standards (MEPS) are one of the representative measures. MEPS is an efficiency regulation for induction motors that limits the minimum efficiency with regard to the power of the induction motors, in order to save energy. Studies have been conducted on induction motors to improve the efficiency and to satisfy MEPS. However, It is very difficult to satisfy the efficiency of induction motor for MEPS. Therefore, synchronous reluctance motors (SynRMs) are actively being studied to replace induction motors. In this paper, a SynRM is designed using a Kw-map. Moreover, to improve the output characteristics, the rib thickness of the SynRM is optimized using the response surface method. Finally, the validity of the design method, proposed in this paper is verified with a real test using the prototype.

Study on the Optimal Design of PMa-SynRM Loading Ratio for Achievement of Ultrapremium Efficiency

Globally, the efficiency of industrial motors is regulated through minimum energy performance standards (MEPS) to reduce energy consumption and CO2 emission. Induction motor, used as a representative industrial motor, has a limit to efficiency improvement as the result of the additional copper loss of the rotor. To replace the induction motor, design of synchronous reluctance motor (SynRM) and permanent magnet assisted synchronous reluctance motor (PMa-SynRM), and the application of a small amount of permanent magnet, is actively studied in the industry. However, it is necessary to develop an ultrapremium efficiency motor beyond the superpremium efficiency to fulfill MEPS, which will be strengthened in the future. Therefore, this paper presents the optimal design method of SynRM by using the finite element method and response surface method to achieve superpremium efficiency. Furthermore, the redefinition of the loading ratio with shape parameters, and the design method of PMa-SynRM, using the loading ratio, is proposed to meet the ultrapremium efficiency. It is an effective design method that can shorten the time and process when designing ultrapremium efficiency PMa-SynRM from the existing SynRM, which is already mass-produced.

Design of Synchronous Reluctance Motor Utilizing Dual-Phase Material for Traction Applications

While interior permanent magnet (IPM) machines have been considered the state-of-the art for traction motors, synchronous reluctance (SynRel) motors with advanced materials can provide a competitive alternative. IPM machines typically utilize neodymium iron boron permanent magnets, which pose an issue in terms of price, sustainability, demagnetization at higher operating temperatures, and uncontrolled generation. On the other hand, SynRel machines do not contain any magnets and are free from these issues. However, the absence of magnets as well the presence of bridges and center post limit the flux-weakening capability of a SynRel machine and limit the achievable constant power speed ratio for a given power converter rating. In this paper, a new material referred to as the dual-phase magnetic material will be evaluated for SynRel designs. This material allows for nonmagnetic regions to be selectively introduced in the bridge and post regions, thereby eliminating one of the key limitations of the SynRel designs in terms of torque density and flux weakening. This paper will focus on advanced SynRel designs utilizing dual-phase material targeting traction applications. The paper will provide a detailed comparison between a dual-phase SynRel design, a conventional SynRel design, and a spoke PM design with rare-earth-free magnets. It will highlight the key tradeoffs in terms of power density, efficiency, and flux-weakening capability.

Simple Design Approach for Low Torque Ripple and High Output Torque Synchronous Reluctance Motors

The rotor design of Synchronous Reluctance Motors (SynRMs) has a large effect on their efficiency, torque density and torque ripple. In order to achieve a good compromise between these three goals, an optimized rotor geometry is necessary. A finite element method (FEM) is a good tool for the optimization. However, the computation time is an obstacle as there are many geometrical parameters to be optimized. The flux-barrier widths and angles are the two most crucial parameters for the SynRM output torque and torque ripple. This paper proposes an easy-to-use set of parametrized equations to select appropriate values for these two rotor parameters. With these equations, the reader can design a SynRM of distributed windings with a low torque ripple and with a better average torque. The methodology is valid for a wide range of SynRMs. To check the validity of the proposed equations, the sensitivity analysis for the variation of these two parameters on the SynRM torque and torque ripple is carried out. In addition, the analysis in this paper gives insight into the behavior of the machine as a function of these two parameters. Furthermore, the torque and torque ripple of SynRMs having a rotor with three, four and five flux-barriers are compared with three literature approaches. The comparison shows that the proposed equations are effective in choosing the flux-barrier angles and widths for low torque ripple and better average torque. Experimental results have been obtained to confirm the FEM results and to validate the methodology for choosing the rotor parameters.

Study of the Synchronous Reluctance Motor Design

Abstract The paper focuses on studying the external-rotor synchronous reluctance motor. The analysis is performed to estimate the influence of the number of stator slots and non-magnetic areas in the rotor (i.e., flux barriers) on the electromagnetic torque and torque ripple of the studied motor. It is concluded that the increase in the number of stator slots Z = 6 to Z = 18 causes an approximately twofold decrease in the ripple factor, but torque increases by 5 %. Electromagnetic torque will be increased approximately by 24 %, if non-magnetic flux barriers are created in the rotor of the studied synchronous reluctance motor.

Design of Synchronous Reluctance Motor for Hybrid Electric Vehicles

This paper deals with the design of a synchronous reluctance motor suited for hybrid electric vehicles. The focus is mainly on rotor design: the angles of the flux barrier ends are chosen with the aim of reducing the torque ripple due to the slot harmonics. A comparison among different rotor arrangements (one, two, and three flux barriers per pole) is presented. Furthermore, an improvement in terms of low ripple and high average torque is given owing to the “Machaon” configuration. The current vector control method is used to maximize the torque according to the voltage and current constraints, taking into account the saturation effects. The impact of the electrical design on the mechanical characteristics of the rotor (natural frequencies) is discussed as well. At last, the predicted mechanical characteristics of the reluctance motor are presented: torque versus speed behavior, power losses, and power factor. The efficiency map of the machine is also reported in the whole operating region.

Prospects for Use of Synchronous Reluctance Motors in Low-Power Electrical Devices

Abstract This paper focuses on studying the synchronous reluctance motors as an alternative to low-power commutator motors. Analysis is done for the improved design of synchronous reluctance motor with a segmental external rotor. Relevant equations and a suitable method are proposed for calculating characteristics of the synchronous reluctance motors operating in a specific mode with electronic commutation as switched reluctance motors. It is concluded that synchronous reluctance motors in this mode can provide a wide range of characteristics and are quite competitive with commutator motors used in low-power devices.

Automatic Design of Synchronous Reluctance Motors Focusing on Barrier Shape Optimization

The automated design of synchronous reluctance (SyR) motors based on multiobjective genetic optimization and finite-element analysis is considered in this paper. Three types of barrier shapes are considered, all described by an effective limited set of input variables. The three solutions are investigated to establish which of the geometries can give the best torque output and also which one represents the best compromise between output performance and computational time. The analysis presented in this paper shows that SyR motors designed automatically can give a good performance and can be designed in a reasonable time, and it is also shown that not all design degrees of freedom are useful in terms of motor performance. Two prototypes of automatically designed machines have been fabricated and experimentally compared with a third prototype designed according to state-of-the-art design principles.

Design of Synchronous Reluctance Motors With Multiobjective Optimization Algorithms

The automatic design of synchronous reluctance (SyR) machines is considered in this paper by means of finite-element analysis and multiobjective optimization algorithms (MOOAs). The research focuses on the design of the rotor geometry, which is the key aspect of the SyR machine design. In particular, the performance of three popular MOOAs is analyzed and compared in terms of quality of the final design and computational time. A procedure to minimize the computational burden of the optimized design process is introduced and applied to a three-layer and a five layer rotor. Two prototypes experimentally demonstrate the feasibility of the design procedure.

Metamodels for Optimum Design of Outer-Rotor Synchronous Reluctance Motor

Abstract A new design of synchronous reluctance motor with segment-shaped outer rotor is presented and investigated in this paper. In order to obtain correct recommendations for optimal design of the studied synchronous reluctance motor, analytical relations of motor electromagnetic parameters and geometrical dimensions (also known as metamodels) have been synthesized. Electromagnetic parameters, which have been used for metamodels synthesis, are obtained by means of magnetostatic field numerical calculations with finite element method using software QuickField. The paper includes the analysis of the studied synchronous reluctance motor geometrical parameters (stator outer diameter, height and overlap angle of rotor’s segment-shaped packages) influence on the electromagnetic torque per unit volume. Testing of synthesized metamodels shows that relative difference between the results obtained by numerical calculations and those obtained with the help of synthesized metamodels does not exceed eight percent at experimental points and intermediate points as well. The proposed optimal design of the segment-shaped outerrotor synchronous reluctance motor obtained with the help of synthesized metamodels has been compared with a salient-pole outer-rotor synchronous reluctance motor having ferromagnetic yoke with the same value of the electromagnetic torque. The comparison results of both motors show that the highest value of electromagnetic torque per unit volume can be achieved with the proposed new design of the synchronous reluctance motor with segment-shaped outer rotor.