Analysis Of Electrical Machines Research Articles

Vector magnetic circuit analysis of silicon steel sheet parameters under different frequencies for electrical machines

AbstractSilicon steel sheets (SSSs), serving as the principal constituent of the magnetic circuit in electric machines, necessitates precise modelling and accurate computation using magnetic circuit theory as a prerequisite for analysing the characteristics of electric machines. Nevertheless, the conventional magnetic circuit theory, limited to a single reluctance component, fails to address the phase relationship between magnetomotive force and magnetic flux, and inadequately represents the magnetic flux distribution observed under high‐frequency conditions. Consequently, the existing magnetic circuit model for SSSs remains imperfect in its current state. Fortuitously, the advent of magductance has effectively addressed these challenges. Building upon magductance, this study deduces the fundamental laws and theorem within the vector magnetic circuit theory. Subsequently, a distributed parameter vector magnetic circuit model for the SSSs is constructed, accompanied by the derivation of expressions pertaining to its reluctance and magductance. The authors propose the transfer function composed of reluctance and magductance parameters, successfully resolving the phase between the magnetic circuit vectors, the magnetic flux distribution, and the magnetic circuit loss under different frequencies for SSSs. Finally, experimental findings affirm the efficacy and validity of the distributed parameter vector magnetic circuit model for SSSs. The proposal of vector magnetic circuit theory opens a whole new door for the analysis, computation, and optimisation of electric machines.

Remanufacturing a Synchronous Reluctance Machine with Aluminum Winding: An Open Benchmark Problem for FEM Analysis

The European Union’s increasing focus on sustainable and eco-friendly product design has resulted in significant pressure on original equipment manufacturers to adopt more environmentally conscious practices. As a result, the remanufacturing of end-of-life electric machines is expected to become a promising industrial segment. Identifying the missing parameters of these types of machines will play an essential role in creating feasible and reliable redesigns and remanufacturing processes. A few case studies related to this problem have been published in the literature; however, some novel, openly accessible benchmark problems can facilitate the research and function as a basis for comparing and validating novel numerical methods. This paper presents the identification process of an experimental synchronous machine. It outlines methodologies for identifying material properties, winding schemes, and other critical parameters for the finite element analysis and modelling of electric machines with incomplete information. The machine in question is intended for remanufacturing, with the plan to replace its faulty winding with an aluminium-based alternative. It also serves as an open benchmark problem for researchers, designers, and practitioners.

Consideration of the spatial orientation of magnetic field quantities and tensile mechanical stress in the Finite Element Analysis of electrical machines

Consideration of the spatial orientation of magnetic field quantities and tensile mechanical stress in the Finite Element Analysis of electrical machines

The Unsung Hero of the Electric Vehicle Revolution: The role of computational electromagnetics in electric machine design and analysis

The Unsung Hero of the Electric Vehicle Revolution: The role of computational electromagnetics in electric machine design and analysis

Equivalent 2-D FEA Modeling Method for AC Loss Analysis of High-Speed Electrical Machines With Litz Winding Considering Incomplete Transposition

In high-speed electrical machines, litz wire shows great performance on reducing the AC loss under complete transposition, which is well-known. However, due to technological limitation, its pitch cannot be made to match the stack length in small aspect ratio machines, bringing significant AC loss. And 3D FEA modeling method is too complicated for its twisted structure and time-consuming. This paper proposed an equivalent 2D FEA modeling method for high-speed electrical machines with litz winding. The machine is divided into several parts along the axial equally, and each part is established by a 2D FEA model approximatively in which litz winding transposition is considered. All 2D models are connected in series in field-circuit coupling model. The influences of structural parameters on AC loss are also analyzed, providing guidance for the optimal design of litz winding in high-speed electrical machines.

Analysis of Electrical Machines’ State by Measuring the Interturn Resistance in Its Windings

Diagnostic methods applied in the industry do not allow to control the state of electrical machines windings in working condition and to fix the defect formation in them at the early stages of development. The aim of the work was to develop a method and construct a device that allows measuring interturn resistances in the electrical machines’ windings without the need to remove it from the technological process, and thereby assess its current and future performance.A block diagram of a device for measuring of interturn resistances in the electrical machines’ windings has been developed, a method has been described, and an algorithm for carrying out diagnostic procedures has been developed. Also, as a result of the study, mathematical dependencies were determined that characterize the main operations performed by the device and a mathematical model was developed for obtaining of the interturn resistance value in the diagnosed windings from the value of the measured phase difference for the AIR63V4U3 asynchronous motor.The developed method and a device based on it allow measuring interturn resistances in the electrical machines’ windings without the need to remove it from the technological process and fix the beginning of defect formation, and, thereby, evaluate its current and future performance in real time.

Design, Analysis and Optimization of Electrical Machines and Drives for Electric Vehicles

Electrical machines are the key components in the ongoing energy transition and electrification and will be an integral part of people’s lives in a future low-carbon society [...]

Thermal Analysis of Water-Cooling Permanent Magnet Synchronous Machine for Port Traction Electric Vehicle

To further increase the torque/power density of a permanent magnet synchronous machine (PMSM) employed for a port traction electric vehicle, improving the thermal dissipation capacity of the cooling system used in the PMSM has become more and more important. This paper focuses on the thermal analysis of a water-cooling 200 kW PMSM for a port traction electric vehicle. First, the size parameters of the machine and the thermal property parameters of the materials used for each component are given. Based on the heat transfer theory, a fast evaluation method for a transient temperature rise in the water-cooling machine under multiple operating conditions is proposed. A lumped parameter thermal network (LPTN) model is established, and the temperature distributions of the machine at different operating conditions are analyzed. Second, under the same conditions, based on computational fluid dynamics (CFD), a three-dimensional (3D) CFD model is constructed. The influence of different cooling structures on temperature distribution is studied. The validity of the proposed fast evaluation method for a transient temperature rise in water-cooling machines under multiple operating conditions is verified. Finally, the results of the CFD and LPTN calculation are verified by experiments; the maximum temperature deviation of the rated speed/rated power operating condition is 8.5%. This paper provides a reference for the design and analysis of port traction electric vehicle machines.

Experimental validation of computationally efficient lumped parameter thermal model developed for hybrid excited linear flux switching machine

Regarding thermal analysis of electrical machines, Lumped Parameter Thermal Model (LPTM) is preferred over Thermal Finite Element Analysis (TFEA) due to computational efficiency and ease of model formation. In this paper, thermal performance of the proposed Hybrid Excited Linear Flux Switching Machine (HELFSM) is analysed by proposing computationally efficient LPTM based on differential equations. LPTM is established for worst case scenario i.e., locked-primary and MATLAB software is utilized to solve temperature rise equations. Firstly, to define hot spots of proposed machine, thermal analysis results up to steady state maximum temperature under 100 % duty cycle are investigated. All three heat flow mechanisms i.e. conduction, convection, and radiation are accounted. Secondly, 75 % and 50 % duty cycles solutions for the hottest parts of proposed machine are investigated by LPTM. Finally, 3-D Thermal FEA (3DTFEA) is developed to validate results of proposed LPTM, followed by experimental validations utilizing thermographic analysis.

Temperature-Dependent Ferromagnetic Loss Approximation of an Induction Machine Stator Core Material Based on Laboratory Test Measurements

The accurate measurement and modeling of ferromagnetic material losses are vital issues during the design and analysis of electrical machines. Higher loss values can describe the manufactured rotor and stator machine plates better than the catalog data obtained by standardized measurements using the Epstein frame. In this paper, different temperature-dependent models based on the loss-separation principle are introduced and compared with the measurements. The model parameters are computed from customized laboratory and standardized measurements. The customized measurements based on the stator part of an induction machine in the range of the automotive industry standard, i.e., in [−40 °C, ⋯, 180 °C]. The proposed model and measurement process can be used in the post-processing stage of numerical field analysis to obtain electromagnetic losses according to the agreement between measured and simulated results. During a numerically expensive optimization process, this model can be used to consider the temperature dependence of the losses more accurately. The study shows that more than 50% of loss increase can be measured, compared with the catalog data, if we use the manufactured, stator-based, customized measurements based on the estimation of the iron loss parameters.

Transient analysis of electrical drives: Applications to the permanent magnet synchronous generator

This paper establishes that differential flatness, a property shared by most of the model of electrical drives, allows to perform transient analysis on the models of electrical machines, and especially electric generators which are so important in renewable energy systems (wind turbine, tidal turbine...). Transient analysis of electrical machines is indeed a difficult subject not completely solved today. The possibility to parameterize the trajectories of a system from the differential flatness property gives the possibility to perform simple transient analysis in various operation modes. The example of the Permanent Magnet Synchronous Generator (PMSG) illustrates the paper.

Measurement and Modeling of Magnetic Materials under 3D Vectorial Magnetization for Electrical Machine Design and Analysis

The magnetic properties of magnetic cores are essential for the design of electrical machines, and consequently appropriate mathematical modeling is needed. Usually, the design and analysis of electrical machines consider only the one-dimensional (1D) magnetic properties of core materials, i.e., the relationship of magnetic flux density (B) versus magnetic field strength (H), and their associated power loss under 1D magnetization, in which the B and H are constrained in the same orientation. Some studies have also been performed with the two-dimensional (2D) magnetizations in which the B and H are vectorial, rotating on a plane, and they may not be in the same direction. It has been discovered that the 2D rotational property is very different from its 1D alternating counterpart. However, the magnetic fields in an electrical machine, in particular claw pole and transverse flux machines, are naturally three-dimensional (3D), and the B and H vectors are rotational and may not lie on the same plane. It can be expected that the 3D vectorial property might be different from its 2D or 1D counterpart, and hence it should be investigated for the interests of both academic research and engineering application. This paper targets at a general summary about the magnetic material characterization with 3D vectorial magnetization, and their application prospect in electrical machine design and analysis.

Characterization of Rotational Magnetic Properties of Amorphous Metal Materials for Advanced Electrical Machine Design and Analysis

Amorphous metal (AM), specifically amorphous ferromagnetic metal, is considered as a satisfactory magnetic material for exploring electromagnetic devices with high-efficiency and high-power density, such as electrical machines and transformers, benefits from its various advantages, such as reasonably low power loss and very high permeability in medium to high frequency. However, the characteristics of these materials have not been investigated comprehensively, which limits its application prospects to good-performance electrical machines that have the magnetic flux density with generally rotational and non-sinusoidal features. The appropriate characterization of AMs under different magnetizations is among the fundamentals for utilizing these materials in electrical machines. This paper aims to extensively overview AM property measurement techniques in the presence of various magnetization patterns, particularly rotational magnetizations, and AM property modeling methods for advanced electrical machine design and analysis. Possible future research tasks are also discussed for further improving AM applications.

Particle Swarm Optimization With Varied Social Network for Reliable Parameter Estimation in Thermal Analysis of Electrical Machines

This article presents a new variant of particle swarm optimization (PSO) algorithm, which was developed for a reliable parameter estimation in thermal analysis of electrical machines. The proposed algorithm uses a varied social network, where both number and size of the network (local neighborhoods) are randomly adjusted during the optimization process. Such approach has been introduced here to assure improved diversity of the PSO and consequently a more reliable and robust search of the solution space. A case study parameter estimation for a reduced-order thermal-equivalent-circuit (TEC) of an electrical machine has been used to demonstrate effectiveness of the proposed method. The analyzed black-box parameter estimation relies on the input and output data (demand data) from a short-transient finite-element-analysis (FEA) of a complete machine assembly. The proposed PSO variant has been benchmarked with a selection of the existing state-of-the-art PSO algorithms, which employ alternative social network schemes with the network parameters dynamically varied. The statistical data gathered from multiple runs of the PSO-based estimation suggests that the proposed new approach offers considerable improvements in terms of accuracy, efficiency, reliability, and robustness as compared with the alternative PSO algorithms.

Parallel-in-space-and-time finite-element analysis of electric machines using time step overlapping in a massively parallel computing environment

PurposeThis study aims to enhance the parallel performance of a parallel-in-space-and-time (PinST) finite-element method (FEM) using time step overlapping. The effectiveness of the developed method is clarified in a magnet eddy-current loss analysis of a practical interior permanent magnet synchronous motor (IPMSM) using a massively parallel computing environment.Design/methodology/approachThe developed PinST FEM is a combination of the domain decomposition method as a parallel-in-space (PinS) method and a parallel time-periodic explicit error correction (PTP-EEC) method, which is one of the parallel-in-time (PinT) approaches. The parallel performance of the PinST FEM is further improved by overlapping the time steps with different processes in the PTP-EEC method.FindingsBy applying the overlapping PTP-EEC method, the convergence of the transient solution to its steady state can be accelerated drastically. Consequently, the good parallel performance of the PinST FEM is achieved in magnetic field analyses of the practical IPMSM using a massively parallel computing environment, in which over 10,000 processes are used.Originality/valueIn this study, the PinST FEM based on time step overlapping is newly developed and its effectiveness is demonstrated in a massively parallel computing environment, in which using either the PinS or PinT method alone cannot achieve sufficient parallel performance. This finding implies a new direction of parallel computing approaches for electromagnetic field computation.

Modelling a permanent magnet synchronous motor in FEniCSx for parallel high-performance simulations

There are concerns that the extreme requirements of heavy-duty vehicles and aviation will see them left behind in the electrification of the transport sector, becoming the most significant emitters of greenhouse gases. Engineers extensively use the finite element method to analyse and improve the performance of electric machines, but new highly scalable methods with a linear (or near) time complexity are required to make extreme-scale models viable. This paper introduces a three-dimensional permanent magnet synchronous motor model using FEniCSx, a finite element platform tailored for efficient computing and data handling at scale. The model demonstrates comparable magnetic flux density distributions to a verification model built in Ansys Maxwell with a maximum deviation of 7% in the motor’s static regions. Solving the largest mesh, comprising over eight million cells, displayed a speedup of 198 at 512 processes. A preconditioned Krylov subspace method was used to solve the system, requiring 92% less memory than a direct solution. It is expected that advances built on this approach will allow system-level multiphysics simulations to become feasible within electric machine development. This capability could provide the near real-world accuracy needed to bring electric propulsion systems to large vehicles. • Stable and scalable electric machine analysis is possible using iterative methods. • Open-source solvers can leverage the advantages of high-performance computing. • The parallel performance of FEniCSx exceeds an established electromagnetic code.

A new hybrid analytical model for electromagnetic analysis of wound rotor induction motors

AbstractAccurate modeling of slotting and magnetic saturation effects has been two main challenges for analytical modeling of electric machines. In this article, first, different techniques such as sub‐domain (S‐D) model, winding function theory, magnetic equivalent circuit (MEC) model, and conformal mapping (CM) method are introduced to analytical model and analysis of electric machines. These techniques are also compared in terms of their accuracy, and computational complexity. Second, with respect to the comparison results, a new hybrid analytical model is presented for electromagnetic modeling of wound rotor induction motors, which consider the modeling accuracy of slotting and magnetic saturation effect, simultaneously. In this way, the air‐gap region is modeled by using S‐D model, and the iron parts are considered by using MEC model assisted by CMs. In final, the analytical results are verified by comparing with corresponding results obtained through finite element method and experiment set‐up.

Steady-State Analysis of Electric Machines Using the TP-EEC Method Based on Time-Periodic Conditions in a Rotational Reference Frame

Steady-State Analysis of Electric Machines Using the TP-EEC Method Based on Time-Periodic Conditions in a Rotational Reference Frame

A Magnetic Network Model and Harmonic Analysis of a Canned Switched Reluctance Machine

This article presents a novel network model for magnetic flux and loss analysis of electrical machines. This model enables harmonic analysis and is applied on a canned switched reluctance machine, with emphasis on magnetic can-shield effect. The modeling is featured by identifying airgap flux path structure, combined with a fast calculation method of magnetic saturation and electro-magnetic field interaction due to the use of cans. Finite element (FE) method and measurement are taken as verification.

Two-dimensional steady-state thermal analytical model of permanent-magnet synchronous machines operating in generator mode

PurposeThermal analysis of electrical machines is usually performed by using numerical methods or lumped parameter thermal networks depending on the desired accuracy. The analytical prediction of temperature distribution based on the formal resolution of thermal partial differential equations (PDEs) by the harmonic modeling technique (or the Fourier method) is uncommon in electrical machines. Therefore, this paper aims to present a two-dimensional (2D) analytical model of steady-state temperature distribution for permanent-magnet (PM) synchronous machines (PMSM) operating in generator mode.Design/methodology/approachThe proposed model is based on the multi-layer models with the convolution theorem (i.e. Cauchy’s product theorem) by using complex Fourier’s series and the separation of variables method. This technique takes into the different thermal conductivities of the machine parts. The heat sources are determined by calculating the different power losses in the PMSM with the finite-element method (FEM).FindingsTo validate the proposed analytical model, the analytical results are compared with those obtained by thermal FEM. The comparisons show good results of the proposed model.Originality/valueA new 2D analytical model based on the PDE in steady-state for full prediction of temperature distribution in the PMSM takes into account the heat transfer by conduction, convection and radiation.