International Journal of Applied Electromagnetics and Mechanics - Volume 54, issue 4

Authors: Bu, Wenshao | Huang, Yongquan | Li, Ziyuan | Shi, Haitao | Shi, Jingzhuo

Article Type: Research Article

Abstract: To achieve the radial displacement self-sensing detection of a bearingless induction motor, a prediction model or estimation method of radial displacement based on least squares support vector machine (LS-SVM) is presented. Firstly, the nonlinear relationship between the radial displacement of bearingless rotor and the currents of two sets of stator windings is analyzed. Then, the stator current components of torque windings and suspension windings, and the rotor flux-linkage of torque system are taken as input variables, the acceleration of α and β radial displacement components are taken as output variables, and based on the …regression principle of LS-SVM, the predication model or estimation method of radial displacement based on LS-SVM is designed. Based on this, the radial displacement sensorless control system of a bearingless induction motor is constructed. Simulation results have shown that when the presented displacement estimation method is adopted, quicker tracking speed and higher tracking accuracy of radial displacement can be obtained; meanwhile the control system of bearingless induction motor has stronger ability of anti load torque disturbance. Show more

Keywords: Bearingless induction motor, displacement prediction model, least squares support vector machine, control system, simulation analysis

DOI: 10.3233/JAE-160146

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 597-610, 2017

Authors: Li, Xiangchao | Chen, Liangying | Chen, Rongxu | Zhang, Jing | Xue, Qi

Article Type: Research Article

Abstract: In this paper, we proposed an approach to suppress the lightning electromagnetic pulse for receiver by utilizing lightning protection device. The equivalent circuit model of the antenna in receiving state together with the lightning protection device is established for both theoretical and numerical analysis. The combination wave generator (CWG) was used to generate 8/20 μ s current injected into the return stroke channel, and the induced overvoltage and energy distribution the lightning electromagnetic wave coupled by receivers have been analyzed. Results illustrate that the induced lightning overvoltage can be well suppressed by using the proposed circuit, and the additional …circuit has little effect on the performance of the antenna. The experimental results have good agreement with that of the theory of equivalent circuit. Show more

Keywords: Receiver, suppress, lightning electromagnetic pulse, lightning protection device

DOI: 10.3233/JAE-170012

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 611-626, 2017

Authors: Chiariello, Andrea Gaetano | Formisano, Alessandro | Ledda, Francesco | Martone, Raffaele | Pizzo, Francesco

Article Type: Research Article

Abstract: The mathematical description of 3D magnetic surfaces is of paramount importance in several applications, but the solution can be hard in terms of the computing effort or unsatisfactory in terms of accuracy. The paper proposes an effective methodology based on the tracking of a limited portion of the magnetic field line and on the fitting of the line onto a 3D surface described in a suitable set of 3D shape functions. In this way, the field line plays the role of a non-uniform sampling of the magnetic surface and the minimization of a suitable error allows …the determination of the expansion coefficients. The computational cost of the line tracking can be limited according to the actual precision needs. The proposed approach allows the introduction of a number of indexes suited to estimate the accuracy and, if the case, to indicate how to upgrade the fitting parameters to meet the actual requirements. Show more

Keywords: Nuclear fusion reactor, magnetic surfaces, plasma boundary analytical description, computational electromagnetism

DOI: 10.3233/JAE-170003

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 627-645, 2017

Authors: Li, Xiangchao | Zhang, Jing | Chen, Rongxu | Chen, Liangying | Xue, Qi

Article Type: Research Article

Abstract: In this paper, we demonstrate the coordinated application of voltage switching type surge protective device (SPD) and voltage limiting type SPD utilizing the theory of the wave propagation and circuit. And the connection between the two devices are 3 m, 5 m, 7 m and 10 m length wire, equivalent hollow or magnetic core inductance, respectively. Based on the experimental data, results indicate that as decoupling devices, the wire, the hollow inductance and the magnetic core inductance with the same inductance value are equivalent. Moreover, the inductance between the gas discharged tube (GDT) and the ZnO varistor should be larger …properly, because of the magnetic saturation of the magnetic core inductance. Show more

Keywords: Voltage switching type SPD, voltage limiting type SPD, inductance, coordinated application

DOI: 10.3233/JAE-170005

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 647-654, 2017

Authors: Cai, Changsong | Wang, Junhua | Hu, Meilin | Long, Mengjiao | Zhou, Yingguo

Article Type: Research Article

Abstract: This paper focuses on the electromagnetic properties of new cylinder type twelve-pole permanent magnet eddy current coupling. By combining conventional equivalent magnetic charge method and superposition principle, the analytical calculation model of air gap magnetic field distribution for the cylinder type permanent magnet eddy current coupling is established; by considering the skin effect, the analytical model of eddy current density is set; the analytical model of electromagnetic-transfer torque is given with the demagnetization effect taken into consideration. Based on the established analytical calculation model, the variation law of air-gap magnetic induction intensity, eddy current density distribution and magnetic torque characteristic …curve are analyzed and plotted in detail. At the same time, finite element simulations of the air gap magnetic field, eddy current density and electromagnetic-transfer torque are carried out based on multi-physics, and the results are compared with analytical calculations. Moreover, the paper analyzed the thickness of magnet conductive plate impacts on eddy current and explored relations between torque and coupling distance under different pole pairs. Finally, in order to verify the simulations, the prototype test of torque transfer characteristics is carried out. This paper compares the experimental results with the theoretical analysis and simulation results, and finds out the error is within the allowable range. Show more

Keywords: Permanent magnet eddy current coupling, magnetic field, eddy current, magnetic torque, FEM

DOI: 10.3233/JAE-170006

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 655-671, 2017

Authors: Ren, Xiaojun | Le, Yun | Han, Bangcheng | Wang, Kun

Article Type: Research Article

Abstract: Compared with the traditional vacuum turbo-molecular pumps (TMPs) with oil-lubricated bearings, magnetically suspended TMPs can obtain an ultra-clean and ultra-high vacuum environment. Considering the poor heat dissipation condition of rotor and miniaturization of industrial applications, this paper focuses on loss optimization and thermal analysis of a heteropolar magnetic bearing (HeMB) for a vacuum TMP. Loss and mass of HeMB were minimized with multi-objective genetic algorithm optimization. Thermal performance predictive calculation is conducted by analytical model and by finite element method (FEM), respectively. To verify the optimization design and anylysis, the relative tests were implemented on a prototype. For the mechanical …and electrical products applied in vacuum, loss optimization and thermal analysis at design stage are very important to the implementation of the system performance. Show more

Keywords: Loss optimization, thermal analysis, magnetic bearings, vacuum molecular pump

DOI: 10.3233/JAE-170009

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 673-690, 2017

Article Type: Other

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 54, no. 4, pp. 691-697, 2017