Design Of Synchronous Machine Research Articles

Design and shape optimization of interior permanent magnet synchronous machine based on hybrid cores

By designing stator teeth using grain-oriented sheets (GO) and other parts still with non-grain-oriented sheets (NGO), the electromagnetic performance of the interior permanent magnet synchronous machine (GO-IPMSM) can be improved greatly. As the stator core of the designed GO-IPMSM is a hybrid core that is composed of two different silicon sheets, both the electromagnetic and mechanical performances are affected by the stator joint shape between GO and NGO sheets. Meanwhile, with the adoption of GO, the torque ripple of GO-IPMSM is increased though the average torque is increased as well. For reducing the torque ripple, optimizing the rotor barrier shape is an effective way. In this paper, the piecewise linear interpolation method is employed for establishing the stator joint shape between GO and NGO sheets, and the polynomial method is proposed to establish the rotor barrier shape. Through the analysis, it can be seen that the stator joint shape plays a strong role in affecting the mechanical performance of the GO-IPMSM, while the effect on the electromagnetic performance is weak. The genetic algorithm is used to optimize the rotor barrier shape for achieving high average torque and low torque ripple. Lastly, a quick and accurate efficiency map calculation method based on the Kriging model is proposed for GO-IPMSM with less finite element method (FEM) samples are required.

Selecting the Best Permanent Magnet Synchronous Machine Design for Use in a Small Wind Turbine

The article describes the selection of a permanent magnet synchronous machine design that could be implemented in a small wind turbine designed by the GUST student organization together with researchers working at the Technical University of Lodz. Based on measurements of the characteristics of available machines, eight initial designs of machines with different rotor designs were proposed. The size of the stator, the number of pairs of poles, and the dimensions of the magnets were used as initial parameters of the designed machines. The analysis was carried out about the K-index, the so-called index of benefits. The idea was to make the selected design as efficient as possible while keeping production costs and manufacturing time low. This paper describes how to select the best design of a permanent magnet synchronous generator intended to work with a small wind turbine. All generator parameters were selected keeping in mind the competition requirements, as the designed generator will be used in the author’s wind turbine. Based on the determined characteristics of the generator variants and the value of the K-index, a generator with a latent magnet rotor was selected as the best solution. The aforementioned K-index is a proprietary concept developed for the selection of the most suitable generator design. This paper did not use optimization methods; the analysis was only supported by the K-index.

Circular Economy Aspects of Permanent Magnet Synchronous Reluctance Machine Design for Electric Vehicle Applications: A Review

Innovative technological solutions have become increasingly critical in addressing the transportation sector’s environmental impact. Passenger vehicles present an opportunity to introduce novel drivetrain solutions that can quickly penetrate the electric vehicle market due to their shorter development time and lifetime compared to commercial vehicles. As environmental policy pressure increases and customers demand more sustainable products, shifting from a linear business approach to a circular economy model is in prospect. The new generation of economically competitive machines must be designed with a restorative intention, considering future reuse, refurbishment, remanufacture, and recycling possibilities. This review investigates the market penetration possibilities of permanent magnet-assisted synchronous reluctance machines for mini and small-segment electric vehicles, considering the urban environment and sustainability aspects of the circular economy model. When making changes to the materials used in an electric machine, it is crucial to evaluate their potential impact on efficiency while keeping the environmental impact of those materials in mind. The indirect ecological effect of the vehicle’s use phase may outweigh the reduction in manufacturing and recycling at its end-of-life. Therefore, thoroughly analysing the materials used in the design process is necessary to ensure maximum efficiency while minimising the environmental impact.

Design and Optimization of a Five-Phase Permanent Magnet Synchronous Machine Exploiting the Fundamental and Third Harmonic

This paper deals with the design of five-phase permanent magnet synchronous machines (PMSMs) exploiting the third harmonic for torque generation. Through the optimization of the stator size and rotor structure, the objective functions related to mass and electric losses are minimized for a targeted electromagnetic power (10 kW and 400 rpm) and a given volume. The study takes into account saturation, thermal, electrical and mechanical constraints. On that note, a 1D analytical magnetic model, considering the existence and use of the third harmonic, is presented. The design optimization then shows how the use of harmonic 3 can improve the machine’s performance. It will be shown that, for a given electromagnetic torque, taking the third harmonic into account in the sizing process leads to a mass reduction that can reach 20% and electrical losses that can go up to 21%. A finite element analysis model of the five-phase PMSM is then established in order to verify the results of the optimization and validate them.

Cooling Structure Design of High-Speed Permanent Magnet Synchronous Machine With Axial Ventilation Self-Cooling Rotor

Cooling Structure Design of High-Speed Permanent Magnet Synchronous Machine With Axial Ventilation Self-Cooling Rotor

Torsional Vibration Analysis and Optimization Design of the Surface PM Synchronous Machine with Reduced Torque Ripple

Torsional Vibration Analysis and Optimization Design of the Surface PM Synchronous Machine with Reduced Torque Ripple

Theoretical Analysis for Rapid Design of Hybrid Excitation Synchronous Machine With Consequent Pole Rotor

Theoretical Analysis for Rapid Design of Hybrid Excitation Synchronous Machine With Consequent Pole Rotor

Multi-Objective Optimization Design of Hybrid Excitation Double Stator Permanent Magnet Synchronous Machine

Multi-Objective Optimization Design of Hybrid Excitation Double Stator Permanent Magnet Synchronous Machine

Preliminary Design and Comparative Analysis of a New Synchronous Reluctance Machine With Hybrid Cores

Preliminary Design and Comparative Analysis of a New Synchronous Reluctance Machine With Hybrid Cores

Simulation of the Circulating Bearing Currents for Different Stator Designs of Electric Traction Machines

Pulse–width modulated inverters are commonly used to control electrical drives, generating a common mode voltage and current with high–frequency components that excite the parasitic capacitances within electric machines, such as permanent magnet synchronous machines or induction machines. This results in different types of bearing currents that can shorten the service life of electric machines. One significant type of inverter–induced bearing currents are high–frequency circulating bearing currents. In this context, this work employs finite element analysis and time-domain simulations to determine the common mode current and circulating bearing current for various permanent magnet synchronous machine designs based on the traction machines of commercial electric vehicles with a focus on the stator. The results suggest that the ratio between the circulating bearing current and common mode current is much smaller in permanent magnet synchronous machines for traction applications than previously established in conventional induction machines, with values below 10% for all analyzed designs. A further increase in the robustness of such electric machines to the detrimental effects caused by the inverter supply could be achieved by reducing the parasitic winding–to–stator capacitance or by increasing the stator endwinding leakage inductance.

An efficient combination of topology optimization and parameter optimization for electromagnetic devices

A novel hybrid optimization (HO) method efficiently combines parameter optimization (PO) and topology optimization (TO) is proposed. The novelty concerns introducing the mesh deformation technique for model regeneration to make a connection between the TO and PO, in this way, the geometric features can be inherited in iterative optimization to fasten the convergence. The proposed HO is applied to the optimal design of a baseline V-type permanent magnet synchronous machine (PMSM), in which the topology of air barriers and the layout parameters of permanent magnets (PMs) are simultaneously optimized, for torque property enhancement. Comparative numerical results show that the proposed HO is more efficient in optimal solution searching compared with traditional methods, as good topological features can be inherited in the iterative optimization. The numerical results also indicate that the proposed HO has good compatibility with different solvers, it can always provide good convergence to provide PMSM designs with excellent torque property when an evolutionary algorithm such as a genetic algorithm and evolution strategy is used as the solver.

Multi-objective optimization design of permanent magnet linear synchronous machine based on stratified strategy

This paper proposes a multi-objective stratified optimization (MOSO) design for a permanent magnet linear synchronous machine (PMLSM) to obtain higher thrust and suppress the thrust ripple. MOSO can combine the advantages of different optimization methods and have fast and efficient optimization characteristics. Based on the parametric analysis of the influence of the auxiliary tooth size and the end-tooth width on the thrust performance, the sensitive variables are quickly filtered by using the Taguchi method. The response surface model (RSM) is built by adopting the central composite design (CCD) based on the sensitive variables. Moreover, the stratified optimization design of the PMLSM is completed by combining with the multi-objective particle swarm optimization (MOPSO) to achieve a balance between local and global search. Finally, a prototype is manufactured, and experiments are implemented to verify the proposed method.

Optimization of PMSMs Considering Multi-Harmonic Current Waveforms: Theory, Design Aspects, and Experimental Verification

This article is about investigating the potential of multi-harmonic design of permanent magnet synchronous machines. Thereby, multi-harmonic refers to the temporal periodic characteristics of linked fluxes and currents of the stator phases in order to ensure high-efficient operation with very low torque ripple. At first, a suitable model allowing for multi-harmonic currents evaluation is derived. Consequently, an interior-rotor IPM machine is studied. In order to have a fair comparison with conventional PMSMs featuring sinusoidal currents, an optimization scenario is defined where the same outer dimensions as well as magnet and copper volume for both design variants are considered. The use of multiple current harmonics requires a dedicated strategy for evaluating machine designs, as the conventional <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$dq$</tex-math></inline-formula> -grid analysis cannot be utilized. The introduced approach is applied and results of the optimization are illustrated. Prototypes were manufactured and machine designs were subsequently evaluated through experiments. A valuable lesson learned during practical implementation regarding rotor angle determination is highlighted. Measurement results reveal that adding more degrees of freedom in terms of multiple harmonics can give significant improvements for performance measures efficiency and torque ripple. This particularly holds if the harmonics are already considered throughout the machine design and optimization process, rather than only at post-processing stage.

High Speed Permanent Magnet Assisted Synchronous Reluctance Machines – Part I: A General Design Approach

The design of synchronous reluctance machines with and without permanent magnets assistance constitutes a challenging engineering task due to the numerous design variables and performance indexes to be considered. The design complexity increases even further when the application requires high speed operation, with consequent rotor structural constraints and related effects on the electromagnetic performance. Structured as two-parts companion papers, this work proposes a comprehensive design procedure able to consider all the non-linear aspects of the machine behaviour, greatly reducing the number of independent design variables, without worsening the computational burden. In particular, the non linear behaviour of the rotor iron ribs and the effect of the permanent magnets on the structural design are all taken into account with the proposed iterative design procedure targeting the achievement of a desired power factor. The proposed method will be then used to draw some preliminary design considerations highlighting the several trade-offs involved in the design of high speed permanent magnet assisted synchronous reluctance machine. Part I is setting the theoretical bricks that will be further expanded and experimentally validated in the companion paper Part II.

Optimal Design of Permanent Magnet Synchronous Machine Based on Random Walk Method and Semi 3D Magnetic Equivalent Circuit Considering Overhang Effect

Permanent magnet synchronous machines (PMSMs) with an overhang structure can increase power density by compensating for the increased magnetic energy of permanent magnets. To analyze the overhang structure, a three-dimensional (3D) analysis of PMSMs is essential. However, 3D analysis takes a long time and the modeling process is complicated in the initial design stage. To overcome these problems, a magnetic equivalent circuit technique is applied to the 2D model. In this paper, an optimal design method for PMSMs with an overhang structure is proposed based on the semi 3D magnetic equivalent circuit (MEC) and random walk method. By using semi 3D MEC, it is possible to quickly analyze PMSM and obtain accurate electromagnetic analysis results considering the overhang effect. Moreover, the volume and weight of PMSM can be minimized by optimizing the rotor’s four design parameters using a random walk algorithm. To obtain high efficiency, the objective function is selected so that copper loss is minimized under the same constraints. The validity of the proposed design technique is verified by comparing the analysis results of semi 3D MEC and 3D finite element method for the derived optimal model.

Design and Analysis of Parallel-Connected Grid-Forming Virtual Synchronous Machines for Island and Grid-Connected Applications

Transmission system operators (TSOs) are increasingly requesting frequency support, reactive power compensation, and grid-forming capability to power plants interfaced by power converters. In these plants, a large number of converters is operated in parallel and all of them should be adequately coordinated to provide these services. For that purpose, the virtual synchronous machine (VSM) control technique is commonly adopted. However, the dynamic characteristics of the whole plant depend on the number of converters connected, their size, control parameters, and electrical interconnections. This makes it difficult to know the aggregated dynamic characteristic of the plant and how each VSM contributes to the plant response. In this article, the operation of VSMs in parallel configuration for island and grid-connected applications is studied. The developments make it possible to adapt the VSMs parameters so that the grid sees the power plant as an equivalent generator whose low-frequency characteristics do not vary with the number of converters in operation. The developments were validated in a laboratory consisting of four 15&#x00A0;kVA converters operating as VSMs, and a grid emulator.

Absolutely Feasible Synchronous Reluctance Machine Rotor Barrier Topologies with Minimal Parametric Complexity

The first step in the synchronous reluctance machine design is the selection of rotor flux barrier type. The literature provides various barrier construction methods with a common goal of reducing parametric complexity. However, too excessive simplification can lead to decreased performance, while overly complex geometries tend to increase optimization time. This paper presents a set of novel flux barrier construction methods with an increased degree of freedom and minimal geometrical complexity. The paper proposes four topologies based on circular, hyperbolic, and original Zhukovsky lines. When considering parametrization complexity, the original Zhukovsky type is the simplest, but it has barrier depth limitations. Other topologies have equal complexity. The paper proposes a novel Modified Zhukovsky variable depth type based on geometrical conformal mapping of the original Zhukovsky lines. The step-by-step construction of each topology is presented in a form of pseudo-code with detailed comments and illustrations. Overall, the presented research provides a valuable starting point for the designer who wants to investigate different smooth rotor barrier topologies.

Hybrid Excited Synchronous Machines

Hybrid excited synchronous machines (HESMs) combine permanent-magnet (PM) excitation and wound field (WF) excitation. The goal of hybrid excitation is to combine the advantages of PM excited machines and WF synchronous machines. HESM have been identified as one of the emerging technologies for modern energy conversion systems. They have been the subject of many review articles. The principle of hybrid excitation allows solving many drawbacks related to PM electric machines operation: flux weakening, energy efficiency, and PMs price fluctuation. It helps to introduce an additional degree of freedom in the design of synchronous machines, and allows therefore an easier adaptation of PM synchronous machines to a wider applications scope. To this additional degree corresponds the possibility of adjusting the contribution of the two magnetic field sources: PM and WF. The use of this technology for electric traction has been the subject of many scientific and technical contributions. In this contribution, the emphasis will be put on the use of these machines as generators in transportation applications and renewable energy applications. The design and operation of three particular structures will be presented. Two of them have been designed as generators for transportation applications, and the third one has been designed as generator for renewable energy conversion. All of them are flux switching hybrid excited synchronous machines (FSHESM).

Study on the Design of Six-Phase Surface Inset Permanent Magnet Synchronous Generator and Motor Considering the Power Factor and Torque Ripple

In this article, a design of six-phase surface inset permanent magnet synchronous machine (SIPMSM) with the open slots is performed considering the power factor and torque ripple. Because of the reluctance torque component by the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis core thickness of rotor, an SIPMSM has the high torque density but the large torque ripple. To overcome the large torque ripple, there are various design methods. In case of SIPMSM with the open slots, the tapering of shoe and the notch of stator and rotor cannot apply the tapering that is applied to magnet, but the torque density and power factor decrease because the linkage flux by the permanent magnet reduces. Therefore, the thickness of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis core and tapering magnet has the tradeoff between the performance and the torque ripple. In this article, the characteristic according to the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis core thickness and tapering magnet is analyzed based on a finite element analysis (FEA). Furthermore, the optimal design is proposed using the performance map based on the tapering of magnet and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$q$ </tex-math></inline-formula> -axis thickness of core. For the design of a basic model, pole–slot combinations are compared with the torque of SIPMSM according to the current phase angle. Considering the performance, the basic SIPMSM is selected for the optimal design. Based on the basic SIPMSM, the optimal design is performed based on the optimal design parameters considering the power factor and torque ripple.

Comprehensive Design and Analysis of an Interior Permanent Magnet Synchronous Machine for Light-Duty Passenger EVs

This paper presents a detailed process for the design of interior permanent magnet synchronous machines (IPMSMs) for electric vehicle (EV) applications. First, a comprehensive design process featuring two objectives and three constraints is proposed to realize an optimal IPMSM design that can satisfy the key performance requirements for an EV application. The objectives and constraints were carefully selected and designed to obtain a balance between performance, efficiency, and cost. Because the inductances and magnet flux linkage of the machine are key design parameters for attaining optimal flux-weakening capability, the impact of the machine dimensions on these two parameters is thoroughly investigated and explained using both analytical and numerical techniques. Additional analyses including normalized key performance metrics and the impact of short-circuit faults in PM machines with three different characteristic current values (1, 1.3, and 2.6 pu) are also provided, highlighting the advantages and limitations of the three baseline designs.