International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 1-2

Authors: Chen, Feng | Zhao, Yanzhen | Ma, Xikui

Article Type: Research Article

Abstract: Based on the formulae for calculating ac resistance of long solenoid and strip conductor, an improved formula for single-layer air-core solenoid was derived. The proposed formula is more accurate and practical by virtue of the asymptotic matching model and the least squares method. Moreover, finite element simulations are performed to illustrate the accuracy of the proposed formula.

Keywords: Single-layer air-core solenoid, asymptotic matching model, least squares method

DOI: 10.3233/JAE-2010-1141

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 423-430, 2010

Authors: Seo, Jang-Ho | Jung, Hyun-Kyo

Article Type: Research Article

Abstract: In this paper, we investigated the effect of slot-pole combination on rotor loss in interior permanent magnet synchronous machine (IPMSM) with distributed armature windings. In order to study the characteristics of the rotor losses, two machines for high-speed operation such as electric vehicle were designed. One is fractional slot winding and the other is conventional one. Based on 2-D time-stepped finite element method (FEM) we analyzed both iron loss and eddy-current loss in the permanent magnet …of the machines according to their driving conditions. From the analysis results, it was shown that rotor iron loss and eddy-current loss of PM of machine employing fractional slot-winding is definitely large at load condition. Show more

Keywords: Distributed armature winding, electric vehicle, fractional slot per pole, iron loss, interior permanent magnet synchronous machine

DOI: 10.3233/JAE-2010-1142

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 431-438, 2010

Authors: Cheng, Yonghong | Jiang, Lili | Hu, Dike | Xie, Xiaojun | Li, Mang | Luo, Naidong

Article Type: Research Article

Abstract: Dielectric property of materials is one of the most fundamental characters. In recent years, there is an increasing interest in the dielectric properties of composite, which consists of matrix and inclusion materials. The volume ratios, component geometry, distribution types of inclusion determine the performance of composite. In this paper, in order to take the factors mentioned above into account, a cubical model and an ellipsoidal inclusion model which contain variables are selected. This article firstly uses …a complex method to discretize the models, and then optimize the discretizition process. After getting the capacitance of every part with basic formula and integral, an electric network is put forward to substitute the original model. It is used to investigate the dielectric property. The relationships between static effective permittivity and the volume ratio, the shape of the inclusion are analyzed. The results obtained by the proposed method are compared with the results got by Maxwell Garnett, logarithmic, Bruggeman and experiment data. The comparison results show the proposed approach has great advantages and different model has specific scope. Show more

Keywords: Electric network, dielectric property, composite

DOI: 10.3233/JAE-2010-1143

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 439-445, 2010

Authors: Kunihiro, Naoki | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents magnetic characteristic analysis of an induction motor model core considering two-dimensional vector magnetic properties. In order to reduce rotational iron losses, which generate in the stator core, we tried to make holes at the tooth base parts. As a result, the rotational flux distribution was effectively controlled by making holes. The results showed that reduction of the total iron loss might be possible by finding out effective holes' size, shape and position.

Keywords: Induction motor, hole, two-dimensional vector magnetic properties, iron loss

DOI: 10.3233/JAE-2010-1144

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 447-456, 2010

Authors: Liu, Yanqin | Wang, Shuhong | Meng, Xiangjun | Qiu, Jie | Feng, Bin | Wei, Caixia | Liu, Fanghua

Article Type: Research Article

Abstract: In this paper, the kinetic characteristics of high voltage power transformer under short-circuit operation are simulated and the influence of prestress is analyzed for the winding stability. Firstly, the finite element method (FEM) is applied to calculate the leakage magnetic field of transformer and electromagnetic force of windings. Secondly, the axial electromagnetic force under short-circuit condition acts on the transformer windings, which are regarded as complex viscoelastic system. The characteristics of the vibration …responses, such as dynamic displacement and dynamic force, are illustrated and their frequency responses are analyzed. Finally, the relationship between prestress and peak value of dynamic force, and as well as displacements of each pancake coil, are discussed. Show more

DOI: 10.3233/JAE-2010-1145

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 457-464, 2010

Authors: Guo, Liuming | Wang, Shuhong | Guo, Ningning | Qiu, Jie | Zhu, Jian Guo | Guo, Youguang | Wang, Yi | Xu, Wei

Article Type: Research Article

Abstract: This paper presents a method based on Current Hoop Model for the analysis and design of induction coilgun. The cylindrically symmetric armature is subdivided into concentric hoops with diverse rectangular cross-sections, in each of which the current is assumed to be uniformly distributed. An equivalent analytical model considering mutual coupling of coils and armature hoops is constructed for dynamic simulation of the coilgun. Based on this model, the self- and mutual-inductances of exciting winding and hoops …are calculated by Neumann method. The circuit equations are solved coupled with the equation of motion of projectile by using the Treanor method to ensure the convergence. Comparison between the experimental results and the numerical results simulated by Finite Element method (FEM) shows the validity of the presented simulation method for coilgun. The optimization of a six-stage coilgun is achieved by employing the genetic algorithm (GA). Show more

Keywords: Electromagnetic coilgun, equivalent analytical model, genetic algorithm

DOI: 10.3233/JAE-2010-1146

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 465-471, 2010

Authors: Wang, Yi | Zhu, Jianguo | Wang, Shuhong | Guo, Youguang | Xu, Wei

Article Type: Research Article

Abstract: In this paper a comprehensive nonlinear model of surface mounted permanent magnet synchronous machine (SPMSM) is proposed considering both the structural and the saturation saliencies to enable the numerical simulation of new rotor position detection algorithms. An experiment platform is carried out to test and collect the incremental inductance values varying again the stator current levels and the rotor position. The Least Relative Residual Sum of Square (LRRSS) method is employed in the nonlinear inductance function …regression. After experimentally identifying out all the parameters, a nonlinear mathematic model of SPMSM is built up. Furthermore, the direct torque control (DTC) scheme is applied to this new model to verify the model and simulate the machine performance. Show more

Keywords: Finite element methods, nonlinear magnetic, PM machines, saturation saliency

DOI: 10.3233/JAE-2010-1147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 473-479, 2010

Authors: Zeng, Zhiwei | Udpa, Lalita | Udpa, Satish S.

Article Type: Research Article

Abstract: Three-dimensional simulation of eddy current testing (ECT) using finite element method (FEM) has been studied over the past three decades and various methods have been developed. In these methods, the ferrite-core probe is meshed together with the sample. Hence, simulation of probe scanning requires re-meshing, which is not only cumbersome but also a major source of computational noise. In this paper, we propose a novel FEM for the simulation of ECT with ferrite-core probe in which …the meshes of ferrite core and sample are generated separately and the coil is not meshed. The new method avoids re-meshing for different probe positions and is simple, flexible, accurate, and efficient. Show more

Keywords: Eddy current testing, finite element method, ferrite-core probe, reduced magnetic vector potential

DOI: 10.3233/JAE-2010-1148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 481-486, 2010

Authors: Luo, Ping | Yao, Li-Hai | Yang, Shi-You | Ni, Guang-Zheng

Article Type: Research Article

Abstract: The optimal design of a 300~MJ superconducting magnet using Bi2223/Ag tapes is studied. The multiple solenoid type is used for the HTS magnet in view of reducing the stray field and structural simplicity. The improved particle swarm optimization algorithm is used to optimize the proposed configuration under constraints such as the fixed storage energy, the volume of the superconductor, the stray field and so on. Finally, finite element method (FEM) is used to validate the storage …energy, the magnetic field, the force in a single solenoid and the stress constraint of the optimal structure. Show more

Keywords: HTS tapes, optimal design, multiple solenoid type

DOI: 10.3233/JAE-2010-1149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 487-493, 2010

Authors: Murakami, Iwanori | Yoshizawa, Akinori | Kobayashi, Yuusuke | Ando, Yoshinori | Yamada, Kou | Nagaya, Kosuke

Article Type: Research Article

Abstract: In this research, we propose the high-TC superconducting levitation synchronous motor that the levitation, the drive, and the vibration suppression are possible with the single disk type rotor composed by some permanent magnets. The center of gravity position is low because this rotor is the single disk structure, and the pitching doesn't occur easily. The displacement of the horizontal direction when the levitation rotor rotates is measured with the laser displacement meter. And, the vibration is …controlled by feeding back this whirling speed to an damper. The High-TC Superconducting Levitation synchronous motor with such a vibration suppression mechanism is developed, and utility is verified by the experiment. Motion analysis and the numerical analysis of the force of an damper were done. Show more

Keywords: Superconductor, levitation, vibration control, synchronous motor, single disc

DOI: 10.3233/JAE-2010-1150

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 1-2, pp. 495-502, 2010