International Journal of Applied Electromagnetics and Mechanics - Volume 45, issue 1-4

Authors: Choi, Myoung-Hyun | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper proposes a design method considering an irreversible demagnetization, the largest problem of the single-phase LSPM using ferrite on start-up. A parameter satisfying maximum output is extracted from the equivalent circuit in steady state, which is used to determine number of turns and shape. Here, back electromotive force and maximum output are selected as design variables for minimizing the effect of demagnetization and size, and the optimal design point is determined with consideration on the …efficiency and maximum output of the single-phase motor. Show more

Keywords: Design methodology, line-start permanent magnet, synchronous machines

DOI: 10.3233/JAE-141845

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 307-313, 2014

Authors: Kim, Bo-Mi | Choi, Myoung-Hyun | Park, Kwan-Tae | Kim, Byung-Taek

Article Type: Research Article

Abstract: In this paper, the analysis method is proposed to analyse the performance of the interior permanent magnet synchronous motor (IPMSM) considering the thermal characteristic. An accurate motor characteristic analysis is conducted by presenting the changes in circuit parameter due to the temperature rise and connecting them to thermal equivalent circuits. The arbitrary motor is selected to compare the test results and analysis results to validate the proposed characteristic analysis method.

Keywords: Equivalent circuit, interior permanent magnet synchronous motor, thermal model

DOI: 10.3233/JAE-141846

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 315-321, 2014

Authors: Cheng, Yuhua | Chen, Yifan | Jiang, Jixiang | Bai, Libing | Zhang, Bing

Article Type: Research Article

Abstract: According to the lift-off effect of eddy current testing, a ferromagnetic absorbing coating thickness gauge was proposed in this paper. After comparison, hyperbolic regression model was adopted to estimate the relationship between the detecting coil impedance and the absorbing coating thickness. An efficient probe with high quality factor and temperature compensation was developed. At the same time, a novel and more flexible calibration method was designed in this paper to improve the measurement …accuracy. The experimental results show that the thickness measurement error is less than 0.02 mm, which proves the validity of this absorbing coating thickness gauge. Show more

Keywords: Lift-off effect, eddy current testing, absorbing coating, hyperbolic regression model

DOI: 10.3233/JAE-141847

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 323-330, 2014

Authors: Lee, Woo Youl | Kim, Yong Bae | Shin, Pan Seok

Article Type: Research Article

Abstract: A rotor slot shape of induction motor for electric vehicle is optimized by FEM with the numerical techniques. To optimize the rotor slot shape, two objective function and 3 variables are defined, and the optimization algorithm is developed. To verify the program, 4 poles 44 kW induction motor is modeled, simulated and analyzed by the program. The optimized rotor slot shape result makes reasonably good improvement to increase torque and efficiency of the motor performance.

Keywords: Induction motor, rotor slot, optimum design, shape optimization

DOI: 10.3233/JAE-141848

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 331-336, 2014

Authors: Lee, Jung Ho | Kim, Young Hyun

Article Type: Research Article

Abstract: This study deals with the dynamic characteristic analysis of a Linear Induction Motor (LIM), using a finite element method in which a moving mesh technique is considered. The focus of this paper is to show the suitability of an on-line observer system for position sensorless control of a LIM under phase asymmetry, saturation and iron loss. Comparisons are given both from the angle of the observer and that of the proposed FEA method of a linear induction motor. …The position control system is realized, and the effectiveness of the observer system for the flux angle is verified by experimental results. Show more

Keywords: LIM, FEM, observer system, sensorless vector control

DOI: 10.3233/JAE-141849

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 337-344, 2014

Authors: Lee, Jung Ho | Kim, Young Hyun

Article Type: Research Article

Abstract: This paper deals with characteristics evaluations for PM magnetization with a stator coil in a post-assembly Line Start Permanent Magnet Motor (LSPMM), using a coupled Finite Element Method (FEM) and Preisach modeling. The focus of this paper is characteristics analysis, relative to magnetizing direction and the quantity of permanent magnets due to eddy currents which occurr in the rotor bar during post-assembly magnetization and which effect Nd-Fe-B magnets.

Keywords: Permanent magnets, FEM, preisach modeling, LSPMM, stator coil magnetization

DOI: 10.3233/JAE-141850

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 345-351, 2014

Authors: Mao, Boyong | Xie, Shilin | Zhang, Xinong

Article Type: Research Article

Abstract: A new identification method for impact loads is proposed based on the transient statistical energy analysis theory. The load identification problems of structure subjected to single excitation are classified into three cases according to the completeness of load location information and subsystem response set. The input energy of impact load and the load location is firstly identified from the averaged vibration energy responses of subsystems according to energy balance equation for three cases. The load amplitude …spectrum is thereafter derived under the assumption of constant value of itself from the identified input energy within each analytical frequency band. Finally, the time history of impact load is further determined for the given load time domain waveform using a developed fitting method. The experimental studies of impact load identification are conducted on a plate-shell assembled structural system. The results show that the location and input energy of impact load can be identified with fairly accuracy using the presented identification method. Besides, both the load spectrum and time history of impact load have good agreements with the measured ones. Show more

Keywords: Load identification, impact load, transient statistical energy analysis, input energy, time history

DOI: 10.3233/JAE-141851

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 353-361, 2014

Authors: Sim, Da-Hee | Jang, Jin-Seok | Jeong, Jin-Chan | Kim, Byung-Taek

Article Type: Research Article

Abstract: This paper investigates optimal design of shoe shape so as to reduce cogging torque of variable-flux (surface permanent magnet synchronous motor) SPMSM using two type of magnets. First, it suggests numerical analysis method of cogging torque of motor organized by two types of magnet. With the numerical method, it designs shoe shape of stator that cogging torque is minimized. Finally, it verifies effectiveness of design using the finite-element analysis.

Keywords: Cogging torque, numerical method, SPMSM, variable-flux

DOI: 10.3233/JAE-141852

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 363-369, 2014

Authors: Cai, Wenlu | Chen, Hong-En | Xie, Shejuan | Li, Yong | Chen, Zhenmao | Uchimoto, Tetsuya | Takagi, Toshiyuki | Kensuke, Yoshihara

Article Type: Research Article

Abstract: Non-destructive evaluation (NDE) techniques are indispensable for inspection of damage in structures of carbon steel, which is widely used in many industries. In this paper, experimental and numerical studies were conducted to investigate the electromagnetic property variations of carbon steel Q195 due to plastic strain by using the 4-probe potential drop method and ECT aiming at NDE applications. A series of specimens were fabricated and uniform global plastic strains of different levels were introduced to the …specimens by tensile testing. 4-probe potential drop measurements were carried out to obtain the conductivity information at first. It is found that the macro conductivity is not affected significantly by the plastic strain once taking into account the influence of the cross-sectional area reduction of the specimens. Combining the results of numerical analysis using a code of A_r formulation with the measured ECT signals, the permeability of specimens with various plastic damages was evaluated through inverse analysis. It is proved that the ECT signal change due to plastic damages is mainly caused by the variation of permeability, which gives a good possibility to evaluate the plastic damage with a magnetic NDE method. Show more

Keywords: Electromagnetic properties, plastic strain, carbon steel, numerical simulation, ECT

DOI: 10.3233/JAE-141853

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 371-378, 2014

Authors: Chen, Hong-En | Xie, Shejuan | Zhou, Haiqiang | Chen, Zhenmao | Uchimoto, Tetsuya | Takagi, Toshiyuki | Kensuke, Yoshihara

Article Type: Research Article

Abstract: Magnetic Incremental Permeability (MIP) method practiced as a NDT technique to evaluate the material degradation is based on the eddy current testing in addition to a low frequency bias magnetic field generated by an electromagnetic magnet. To clarify the mechanism of MIP and to find optimal probe design, a numerical method to simulate MIP profile is important. In this paper, a simulation scheme and a numerical code are developed for MIP of ferromagnetic material based on …the simulated polarization strategy and the reduced vector potential formulae. Experiments are also conducted for test-pieces of carbon steel to demonstrate the validity of the proposed scheme. Show more

Keywords: Numerical simulation, magnetic incremental permeability, ferromagnetic material, ECT, nonlinear, static field

DOI: 10.3233/JAE-141854

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 45, no. 1-4, pp. 379-386, 2014