Analysis Of Electrical Machines Research Articles

Reduced order modelling method for electromagnetic analysis of electrical machines

AbstractThis paper presents a workflow to create a reduced order model for the electromagnetic analysis of electrical machines over its operating range so that the stator forces can be exported for mechanical analysis. A permanent magnet synchronous motor developed within the EDISON (Electric Drivetrain Integration by Simulation and OptimizatioN) project is used as a model to validate the workflow. The response surface model approximation method is used to generate the reduced order model, which is then validated by comparing with the results from finite element analyses.

Air‐gap field prediction in tubular doubly sided surface magnet machine using Bessel–Fourier series

Abstract2‐D air‐gap magnetic field distribution is the essential prerequisite of electrical machine analysis. Because of the natural periodicity of rotary machines, Fourier analysis is a suitable choice for air‐gap field prediction. However, due to the end‐effect, periodicity is not present in linear machines and the Fourier series is not appropriate. In engineering mathematics, a rigorous method of solving partial differential equations is the separation of the variables method (SVM) which is based on the hypothesis that the field solution is in the form of the product of two functions of orthogonal directions; for example, in an axisymmetric structure, a longitudinal harmonic function (LHF) and a radial harmonic function (RHF). A particular case of these functions is trigonometric functions, which result in the Fourier series. SVM is imposed in a different manner, where RHF is approximated by the Bessel–Fourier series and consequently LHF has a (piecewise) exponential behaviour. This choice of basis functions not only serves the purpose of modelling the end‐effect but also removes the Gibbs phenomenon, that is, it precisely models discontinuities of flux density at the surface of PMs. A numerical case‐study of a slotless double‐sided linear tubular surface‐PM machine shows that the piecewise exponential approximation can attain 1% error while utilising only three harmonics, whereas the trigonometric approximation, due to the Gibbs phenomenon, slowly arrives at 20% error with 100 harmonics for approximating flux density. Results of both methods were validated using the finite element method (FEM). Additionally, it was discovered that the computational complexity of the model is independent of varying position; therefore, the analytical method could yield the back electromotive force and electromagnetic thrust force for a number of 320 positions at merely 0.2 s while the FEM software required 5 min.

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.

A Comparative Analysis of Rolling-Rotor Electrical Machines of Different Winding Designs

A Comparative Analysis of Rolling-Rotor Electrical Machines of Different Winding Designs

Applying the Sine-Cosine Optimization Algorithm to the Parametric Estimation Problem in Three-Phase Induction Motors

The steady-state analysis of electrical machines requires a detailed characterization of their equivalent electrical circuit, which adequately represents the transformation and interaction between electrical and mechanical energy. This research aims to characterize the equivalent circuit of three-phase induction motors by minimizing the mean square error between the measured and calculated torque variables. These torques are obtained from data provided by the manufacturer, including starting, peak, and full-load torques. A metaheuristic optimization technique is applied to solve the resulting nonlinear programming model based on the interactions between the sine and cosine functions. The numerical results obtained with this algorithm demonstrate its efficiency in terms of response quality, reaching objective function values of less than \(1\times10^{-8}\) with regard to the measured and calculated variables. Simulation results in two test systems allow concluding that the parametric estimation problem in three-phase induction motors is a multimodal optimization problem. This implies a potentially infinite set of solutions that minimize the root mean square error and adequately represent the behavior of the motor's output torque under various probable operating conditions.

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.

Finite Element Analysis of Electrical Machines Used in Two-Frequency Indirect Temperature Rise Tests

Heat runs of large asynchronous machines (AM) are hardly ever conducted under load but with synthetic approaches, such as the two-frequency method. In its classical variant, the AM’s stator is fed by two series-connected synchronous machines (SM) with dif-ferent frequencies, for instance 50 and 40 Hz. While the 50 Hz voltage determines the AM’s flux, the 40 Hz source causes an AM stator current close to its rated value. Together, voltage and current yield approximately full load losses in the AM without mechanical loading. For designing the amortisseurs of the synchronous gene-rators, damper losses were calculated using the Finite Element method. Additionally, calculated full load AM losses were compared against their respective values for the two-frequency method.

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

Design and Modeling Analysis of a Novel Propulsion Electric Machine With Variable Magnetic Pole Topology

Design and Modeling Analysis of a Novel Propulsion Electric Machine With Variable Magnetic Pole Topology

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.