International Journal of Applied Electromagnetics and Mechanics - Volume 50, issue 3

Authors: Wang, Cuo | Li, Xingfei | Kou, Ke | Wu, Tengfei | Long, Chunguo

Article Type: Research Article

Abstract: As common high precision inertial sensors, quartz flexible accelerometers have wide application prospect in many circumstances such as low cost inertial navigation systems. In order to quickly evaluate magnetic field distribution in air-gap of these accelerometers and provide an insightful knowledge for design optimization, we introduced an analytical method based on scalar magnetic potential to describe their magnetic behaviour. Some related Laplace and Poison equations are solved by separating variables and the parameters of the solutions are calculated by a set of linear vector equations considering boundary conditions. Magnetic field computed with the proposed analytical method is proved effective through …finite element method and some preliminary experiments, additionally, the scale factor estimated can be validated by the gravitational field roll-over test. Show more

Keywords: Quartz flexible accelerometer, analytical model, magnetic flux density

DOI: 10.3233/JAE-150027

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 367-377, 2016

Authors: Cheng, Qiang | Zhang, Zhendong | Xie, Nailiu

Article Type: Research Article

Abstract: Power losses are the most significant factors that influence the power efficiency and comprehensive performances of the ultra-high speed solenoid injector, and can also be used to evaluate the rationality of the magnetic circuit structure and driven strategies. In order to investigate the power losses of the gasoline direct injector (GDI), a driver within four different driven strategies has been designed, the power losses and dynamic response have been analyzed by finite element method (FEM) simulation and experimental methods. The transient electromagnetic simulation was used to calculate late the power losses and dynamic response. The total loss distribution and the …change trends of the current and five kind losses were analyzed. The simulation results show that, there were large differences to the power losses of the GDI injector driven by different strategies, eventually impact on the temperature rising, dynamic responses and flow rate of the injector. Because the power losses cannot be measured directly, the temperature rising, current and dynamic responses were analyzed to validate the accuracy of the simulation. The results indicated that, the power losses can be used to predict the comprehensive performances of GDI injector and also can be used to evaluate the driven strategies. Show more

Keywords: Power losses, GDI injector, temperature rising, dynamic response, FEM

DOI: 10.3233/JAE-150082

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 379-394, 2016

Authors: Zhai, Xiao-Min | Yao, Li-Fang | Wang, Hui-Bo | Dong, Jian-Feng

Article Type: Research Article

Abstract: A bilayered chiral structure with double split-ring resonators on both sides of the dielectric substrate is proposed, which can achieve asymmetric transmission of both linearly and circularly polarized waves propagating forward and backward in near-infrared band, in contrast to previously reported chiral structures that can realize asymmetric transmission of either linearly or circularly polarized waves only. In addition, numerical simulation results demonstrate that our scheme can realize multi-band asymmetric transmission with a mutual conversion (x-to-y, and y-to-x) of linearly polarized electromagnetic waves for one propagating direction only. The realization of the multi-band asymmetric transmission can be attributed to the combination …of two independently coaxial split-ring metallic structures. The physical mechanism of linearly polarized wave conversion and asymmetric transmission based on currents distribution and electric fields is also analyzed in detail, respectively. Show more

Keywords: Chiral metamaterials, asymmetric transmission, multi-band

DOI: 10.3233/JAE-150104

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 395-405, 2016

Authors: Yang, Xiao Long | Li, De Cai

Article Type: Research Article

Abstract: To improve the pressure capacity of the magnetic fluid seal with a large sealing gap, a new type of stepped magnetic fluid seals was firstly proposed based on magnetic fluid seal with multiple magnetic sources or stepped labyrinth seals. A universal magnetic fluid seal with two permanent magnets and a diverging stepped magnetic fluid seal have been investigated by experimental methods. The experimental results of the both sealing structures have been compared and analyzed. The results indicate that the diverging stepped magnetic fluid seal shows good performance compared to the universal magnetic fluid seal without stepping structure and it is …an effective method to improve magnetic fluid sealing capacity with a large gap. Show more

Keywords: Magnetic fluid, seal, stepped structure, large gap

DOI: 10.3233/JAE-150117

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 407-415, 2016

Authors: Cheng, Peng | Yang, Fan | Luo, Hanwu | Guo, Haibo | Ran, Wei | Yang, Yongming | Ullah, Irfan

Article Type: Research Article

Abstract: The reactive power compensation is of crucial importance for the safe and stable operation of ultra-high-voltage (UHV) transmission system. The icing and sag can lead to variation of circuit parameters of transmission line, but it is difficult to calculate the reactive power of transmission line with sag or icing by using circuit method. This paper presents a 3-D power transmission model of transmission line based on Poynting vector and finite difference frequency domain (FDFD) method to solve this problem. The method is applied to evaluate the reactive power of the 1000 kV transmission lines with sag and icing, and the …influences caused by icing and sag are discussed. The proposed method for the reactive power calculation of transmission line would provide important reference for the reactive power compensation in the snow-hit areas. Show more

Keywords: Transmission line, Poynting vector, FDFD, reactive power

DOI: 10.3233/JAE-150118

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 417-433, 2016

Authors: Ning, Yinhang | Liu, Chuang

Article Type: Research Article

Abstract: This paper presents a hybrid excitation synchronous machine (HESM). As a new type of machine, the HESM is expected to have the advantage of high power density, high efficiency, and controllable magnetic field. It is essential to give full considerations of the HESM in the design stage. Hence, the electromagnetic and the thermal analysis are paid special attention in this paper. At first, no-load characteristic is introduced, as well as the structure and operating principle of the HESM. The calculated and experimental results agree well. As the heat source of thermal analysis, it is important to predict loss accurately. In …the next step, the iron loss is analyzed by finite element method, including the loss distribution feature and the influence of field current on the iron loss. Considering overheating may result in the irreversible demagnetization of the permanent magnet and insulation failure of coil, a 3-D computational model is created to conduct the thermal analysis using the predicted loss as heat source, based on the theory of heat transfer. The permanent magnet and the field winding, locating in the rotor, are analyzed emphatically due to its weak cooling condition. The calculated temperature by the numerical method is compared with the experimental result. This study can provide some design references for this type of HESM. Show more

Keywords: Hybrid excitation, synchronous machine, electromagnetic characteristic, loss analysis, thermal analysis, finite element method

DOI: 10.3233/JAE-150121

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 435-448, 2016

Authors: Mansouri, Ali | Smairi, Nadia | Trabelsi, Hafedh

Article Type: Research Article

Abstract: The present work deals with the optimization of an in-wheel surface mounted permanent magnet motor (SMPM) with outer rotor and concentrated windings. The main objective of the optimization procedure is to find the optimum design geometry by maximizing the machine efficiency and minimizing its weight. To reach this goal, two objective functions are used. The first leads to a design with high output torque capability and then high efficiency. The second is a requirement imposed by the fact that the machine is directly integrated inside the vehicle wheel, and therefore a light weight is requested. In order to carry out …this study, five multi-objective optimization algorithms were applied: the Genetic Algorithm (GA), the fast elitist multi-objective Genetic Algorithm (NSGA-II), the Adapting Scatter Search for Multi-objective Optimization algorithm (AbYSS), the improved PSO- based Multi-Objective Optimization and a new PSO-based Metaheuristic for Multi-objective Optimization. The reason of testing several intelligence artificial techniques is to find a fast and efficient technique for electrical machines optimization. Based on the objective functions design and the machine constraints, the results obtained by the five algorithms are compared and analyzed. In order to carry out this study, an analytical model describing the geometric, the magnetic and the electric properties of the studied design was firstly developed. Moreover, an optimized machine is chosen and studied by means of finite element analysis (FEA) tool. Then FEA results are compared with those obtained by the optimization procedure. Based on this comparison, a good concordance between the two results is shown. Show more

Keywords: In-wheel permanent magnet motor design, radial flux motor, analytical model, efficiency, weight, optimization, genetic algorithm, swarm particle algorithm, AbYSS algorithm

DOI: 10.3233/JAE-150125

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 449-465, 2016

Authors: Chen, Zhenfei | Li, Zhixin | Ma, Hongzhong

Article Type: Research Article

Abstract: Two kind of nonuniform slot distribution models, the unit machine shift model (Model 1) and the single slot shift model (Model 2), are proposed for reducing cogging torque of surface-mounted permanent magnet (SPM) machines. Further, based on exact subdomain model and Maxwell stress tensor, an analytical model is further built for calculating cogging torque in SPM machines with nonuniformly distributed stator slots. Its accuracy and feasibility have been validated by finite element (FE) method. With the analytical model, effects of slot shift angle on cogging torque are investigated for an 8-pole/12-slot SPM machine. Meanwhile, coupling relationships between shift angle and …other design parameters (slot/pole number, pole arc coefficient and slot opening) are analyzed. In addition, influences of slot shift on back-EMF and electromagnetic torque are also studied. Conclusions are drawn from the analysis and indicate that Model 1 is much better than Model 2 in improving the performances of SPM machine. Show more

Keywords: Cogging torque, exact subdomain model, stator slot shift, surface-mounted permanent magnet (SPM) machine

DOI: 10.3233/JAE-150127

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 467-482, 2016

Authors: Díaz, Guillermo A. | Mombello, Enrique E.

Article Type: Research Article

Abstract: This paper presents new compact analytical expressions for the magnetic field calculation produced by a finite cylindrical sheet. A linearly varying surface current density between the ends of the cylindrical sheet has been assumed as current source. The expressions presented in this work are substantially more compact if compared with the ones currently available in the literature. Since the solutions are given in terms of complete elliptic integrals of the first, second and third kind, and the last two ones diverge at certain arguments, the field expressions also diverge at these critical points, even though the field solution is finite. …These singular points are located at the ends of the current sheet cylinder. New analytical expressions are also presented for these critical points avoiding the singularities in an elegant way. The radial component of the magnetic field strength is separately discussed, and it has been proven that its solution at singular points diverges. To improve the computational performance on the evaluation of magnetic field at critical points, an alternative formulation is presented, where complete elliptic integrals of the second and third kind are replaced with alternative functions. Numerical algorithms for the computation of these functions are also presented. Show more

Keywords: Current carrying cylinder, elliptic integrals, magnetic field, singularity

DOI: 10.3233/JAE-150132

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 483-501, 2016

Authors: Lee, Sung-Ho | Kim, Yong-Jae | Lee, Kyu-Seok | Kim, Sung-Jin

Article Type: Research Article

Abstract: In this paper, the dynamic characteristics of a motor which is usually examined through experiments after manufacturing the prototype was analyzed using the non-linear finite element method (FEM) based on 2-D numerical analysis in combination with the mechanical motion equation. First of all, a 300 W surface permanent magnet (SPM) motor was designed and the static characteristics were analyzed using the sinusoidal current source. In addition, based on the phase voltage and the direct current (DC) link voltage obtained from the static characteristics analysis results, no-load speed analysis and the dynamic characteristics of loading conditions were carried out. Through these …analyses, it was possible to predict the dynamic characteristics of a motor at the design process and to verify the reliability of design. Show more

Keywords: Surface permanent magnet (SPM) motor, dynamic characteristics analysis, static characteristics analysis, finite element method (FEM), mechanical motion equation, sinusoidal current source, sinusoidal voltage source, dynamic characteristics

DOI: 10.3233/JAE-150136

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 50, no. 3, pp. 503-510, 2016