International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Zhang, Xiwei | Li, Lin | Pang, Jian

Article Type: Research Article

Abstract: In this paper, both nanocrystalline alloy (Fe73.5 Cu1 Nb3 Si15.5 B7 ) ribbon samples and toroidal samples (wound ribbon) are annealed at different temperatures in order to consider the influence of inner stress on the magnetization properties. Then the AC magnetization properties of these samples are measured. Combined with the measured results, the influence of inner stress on nanocrystalline alloy’s microstructure is analyzed quantitatively based on the loss separation principle and the statistical theory of loss. By comparing measured macroscopic magnetization characteristics and excess loss, the equivalent stress state of the toroidal sample is evaluated. Furthermore, two kinds of samples’ …excess loss under different annealing temperatures are analyzed, and the effectiveness of stress relief at optimal annealing temperature is validated. Show more

Keywords: Nanocrystalline alloy, loss separation, excess loss, annealing, stress relief

DOI: 10.3233/JAE-201532

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-11, 2020

Authors: Orosz, Tamás | Karban, Pavel | Pánek, David | Doležel, Ivo

Article Type: Research Article

Abstract: Cost optimization of power transformers is a complex engineering task. The design engineers have to solve this multidisciplinary, non-linear optimization problem in a very short-time. Due to the importance of the topic, numerous optimization methods have been developed in the industry to solve this problem. These methods generally use different, simplified two-winding transformer models, where the windings are generally modeled by their copper filling factors. These models cannot consider the eddy current losses and the temperature gradients of the windings properly, because the calculation of these quantities needs knowledge of the conductor dimensions. This paper proposes a novel method, which …uses a general geometric programming search based sub-problem to determine the optimal conductor dimensions for the optimal winding shape. The proposed method considers the temperature gradients of the windings and uses FEM to determine the eddy losses of the windings. The whole optimization process is made by an evolutionary algorithm (NSGA-II)-based search. The paper presents this novel transformer optimization methodology and then illustrates it with a practical example. Show more

Keywords: Optimization, evolutionary computation, FEA, power transformers

DOI: 10.3233/JAE-209504

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-9, 2020

Authors: Bu, Wenshao | Zhang, Fei | Chen, Youpeng | Zhang, Xiaofeng

Article Type: Research Article

Abstract: As for the inverse decoupling control system of a bearingless induction motor (BL-IM), in order to eliminate the influence of rotor resistance variation on its control performance, on the basis of the reactive power calculation of torque system, a novel fuzzy model reference adaptive (MRAS) identification method of rotor resistance is proposed. The reference model and adjustable model of instantaneous reactive power are derived in detail. In order to improve the identification performance of rotor resistance, a fuzzy PI adaptive law based on popov super stability theory is constructed. On this basis, a rotor resistance identifier is constructed, and it …is used to on-line correct the rotor resistance parameter in the inverse system mathematical model of a BL-IM system. Based on the inverse decoupling control system of a BL-IM, the simulation experimental analysis and verification are carried out. The simulation experimental results have shown that when the proposed identification method of rotor resistance is used, not only the identification- and tracking-speed of rotor resistance can be effectively improved, but also the identification accuracy of rotor resistance can be improved; as for the BL-IM system, after the rotor resistance parameter is on-line corrected, not only the inverse dynamic decoupling control performance can be effectively improved, but also the robustness of BL-IM system to the variation of rotor resistance parameters can be improved. Show more

Keywords: Bearingless induction motor, instantaneous reactive power, MRAS rotor resistance identification, fuzzy PI adaptive law, inverse system decoupling control

DOI: 10.3233/JAE-200018

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-20, 2020

Authors: Yuan, Hao | Zhao, Ximei | Fu, Dongxue

Article Type: Review Article

Abstract: In this paper, a novel high-precision motion control is proposed for a permanent magnet linear synchronous motor (PMLSM) servo system, which is vulnerable to the influence of uncertainties. First, the dynamics of the PMLSM with uncertainties are derived. To cater for the parametric uncertainties, the model-based feedforward control is constructed so that the transient response of the system is improved. Moreover, the adaptive jerk control (AJC) scheme based on a robust integral of the sign of the error (RISE) feedback is adapted to restrain the uncertainties such as external disturbance and nonlinear friction in the system. To alleviate the chattering …phenomenon, a novel exponential adaptive law is designed to bound the feedback gain of the jerk, under the condition of the initial term of control efforts considered. Then, the jerk signal is integrated to form the feedback control law, which generates continuous control input and ensures the stability of the system. Compared with sliding mode control (SMC), the experimental results indicate that both the robustness and tracking performance of the system are significantly improved without adding more control efforts. The position tracking error is reduced and high-frequency oscillation is effectively attenuated. Show more

Keywords: Permanent magnet linear synchronous motor (PMLSM), adaptive jerk control (AJC), robust integral of the sign of the error (RISE) feedback, robustness, chattering

DOI: 10.3233/JAE-201558

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-21, 2020

Authors: Shahid, A. | Ali Abbas, M. | Huang, H.L. | Mishra, S.R. | Bhatti, M.M.

Article Type: Research Article

Abstract: The present study analyses the dissipative influence into an unsteady electrically conducting fluid flow embedded in a pervious medium over a shrinkable sheet. The behavior of thermal radiation and chemical reactions are also contemplated. The governing partial differential equations are reformed to ordinary differential equations by operating similarity transformations. The numerical outcomes for the arising non-linear boundary value problem are determined by implementing the Successive linearization method (SLM) via Matlab software. The velocity, temperature, and concentration magnitudes for distant values of the governing parametric quantities are conferred, and their conduct is debated via graphical curves. The surface drag coefficient increases, …whereas the local Nusselt number and Sherwood number decreases for enhancing unsteadiness parameter across suction parameter. Moreover, the magnetic and suction parameters accelerate velocity magnitudes while by raising porosity parameter, velocity decelerates. Larger numeric of thermal radiation parameter and Eckert number accelerates the temperature profile while by enhancing Prandtl number it decelerates. Schmidt number and chemical reaction parameters slowdowns the concentration distribution, and the chemical reaction parameter influences on the point of chemical reaction that benefits the interface mass transfer. It is expected that the current achieved results will furnish fruitful knowledge in industrious utilities. Show more

Keywords: Electrically conducting fluid, Darcy flow, radiation, shrinking sheet, permeable medium

DOI: 10.3233/JAE-201540

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-14, 2020

Authors: Di Barba, Paolo | Mognaschi, Maria Evelina | Wiak, Slawomir

Article Type: Research Article

Abstract: Many-objective problems, characterized by a high-dimensional objective space, are a source of challenge for standard methods of multi-objective optimization. An evolutionary algorithm based on the concept of least-conflict solutions is here presented; the shape design of a IPM motor is considered as the case study. In particular, optimization problems dealing with 3 and 4 objective functions have been solved, respectively.

Keywords: Many-objective optimization, evolutionary computing, finite-element analysis, inverse magnetostatics, permanent-magnet motor

DOI: 10.3233/JAE-209510

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2020

Authors: Rymarczyk, Tomasz | Kozłowski, Edward | Tchórzewski, Paweł | Kłosowski, Grzegorz | Adamkiewicz, Przemysław

Article Type: Research Article

Abstract: The article presents machine learning methods in the field of reconstruction of tomographic images. The presented research results show that electric tomography makes it possible to analyze objects without interfering with them. The work focused mainly on electrical impedance tomography and image reconstruction using deterministic methods and machine learning, reconstruction results were compared and various numerical models were used. The main advantage of the presented solution is the ability to analyze spatial data and high speed of processing. The implemented algorithm based on logistic regression is promising in image reconstruction. In addition, the elastic net method was used to solve …the problem of selecting input variables in the regression model. Show more

Keywords: Electrical tomography, inverse problem, logistic regression

DOI: 10.3233/JAE-209520

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2020

Authors: Takahara, Kazuaki | Hirata, Katsuhiro | Niguchi, Noboru | Amazutsumi, Tomoya

Article Type: Research Article

Abstract: Multi-Degree-of-Freedom (Multi-DOF) actuating systems are usually composed of several single-DOF motors, which results in large, heavy and complicated structures. In order to solve these problems, various multi-DOF spherical actuators have been actively studied. However, a large number of current phases are required in the spherical actuator. In this paper, in order to reduce the number of current phases, a 3-DOF spherical actuator with auxiliary poles which is driven using 5-phase currents is proposed. Finally, the torque characteristics of the proposed actuator are evaluated through 3-D finite element analysis.

Keywords: Multi-degree-of-freedom, spherical actuator, auxiliary pole

DOI: 10.3233/JAE-209514

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2020

Authors: Nobahari, Amin | Vahedi, Abolfazl | Takorabet, Noureddine

Article Type: Research Article

Abstract: Various design approaches have been studied for performance improvement of permanent magnet motors, especially for electric vehicles application. This paper deals with an effective concept that is based on adopting non-traditional geometries for permanent magnet poles. The study focuses on a general methodology for optimal sizing of the rotor poles’ pre-defined geometrical parameters considering certain objectives. For this purpose, the artificial neural network is employed for creating an accurate and simple model to be used in a multi-objective optimization procedure. An interior crescent-shaped permanent magnet motor for an electric motorcycle is studied as a typical case study to prove the …performance of the proposed method. Finite element models are developed to create the required dataset for the modeling stage as well as to verify the results. Show more

Keywords: Permanent magnet motors, design optimization, permanent magnet shaping, ANN model, torque profile, electric motorcycle

DOI: 10.3233/JAE-209512

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2020

Authors: Dems, Maria | Komęza, Krzysztof | Majer, Krzysztof

Article Type: Research Article

Abstract: Reducing motor losses is very important in connection with raising the requirements set by international regulations on reducing electricity consumption. As induction motors are increasingly powered by high-frequency voltage, core losses starting to play a dominant role in motor loss balance. The presented paper shows how to calculate the basic and additional losses in the core of the induction motor, generated by the reluctance and slot harmonics of the magnetic field in the motor and by the higher harmonics produced by the inverter, using analytical and field-circuit methods. The results for motor operation at frequencies of supply voltage 10, 20 …and 350 Hz were presented and compared with the results of measurements. The main achievement is the statement that losses in the core of the motor fed from the inverter should be calculated as the sum of losses generated by individual harmonics both in the motor and generated by the inverter. Show more

Keywords: Induction motor, core losses, additional losses, inverter power supply

DOI: 10.3233/JAE-209506

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2020