International Journal of Applied Electromagnetics and Mechanics - Volume 71, issue S1

Authors: Jankowski, Piotr | Hallmann, Damian

Article Type: Research Article

Abstract: This article presents the results of research on the influence of the distorted induction motor supply voltage on two selected indicators (phase trajectories and Poincare maps) of chaotic behavior observed in the stator current of an induction motor. The tests were carried out with the use of the proprietary engine model realized in the ANSYS Electronics Desktop environment.

Keywords: Subharmonics, interharmonics, induction motor, chaos

DOI: 10.3233/JAE-220204

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S465-S472, 2023

Authors: Ou, Raishin | Gotoh, Yuji

Article Type: Research Article

Abstract: The large-diameter steel pipes are often used in petrochemical plants. In this large-diameter steel pipe, there are many cases where corrosion in the steel pipe is inspected from the outside of the steel pipe. In particular, there is a demand for a method for detecting defects inside or outside the steel pipe from the outer side of the steel pipe at high speed. Therefore, the electromagnetic inspection method is useful for detecting these defects. In the electromagnetic inspection method, using both static (DC) magnetic field and alternating (AC) magnetic field is proposed for inspecting inner side defects as well as …outside defects. On the other hand, the Fourier series expansion of the full-wave rectified wave of the stationary AC magnetic field shows that it is a composite of the DC component and the AC component due to the cosine wave. Therefore, in this research, an inspection method using full-wave rectified AC magnetic field is proposed for inspecting inner side defects as well as surface defects. In this paper, the usefulness of the proposed method is demonstrated by electromagnetic field analysis using the “play model” that takes into account minor loop magnetic properties. In addition, a verification experiment is also carried out. Show more

Keywords: Full-wave rectified AC magnetic field, magnetic flux leakage, opposite side defect, electromagnetic nondestructive testing, 3-D nonlinear FEM taking account of minor loop curve, play hysterons model method

DOI: 10.3233/JAE-220205

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S473-S482, 2023

Authors: Hagisaka, Ami | Niwa, Shotaro | Shiota, Shinya | Gao, Yanhui | Gotoh, Yuji

Article Type: Research Article

Abstract: At geothermal power plants, there is a problem that hot spring water pipes are blocked by the “hot spring scale”. The hot spring water used for geothermal power generation contains calcium, sulfur, and other substances, and the solid material called the “hot spring scale” adheres to the inside of steel pipes, significantly reducing the efficiency of steam transmission. In addition, there are maintenance costs to remove the “hot spring scale” inside the steel pipes. And it is important to evaluate the thickness of the hot spring scale inside the steel pipe. In this paper, a non-destructive sensor that is evaluated …the thickness of the hot spring scale inside the steel tube from the outside of the steel pipe is proposed. The proposed sensor is consisted of a permanent magnet, an alternating excitation coil and an acceleration sensor. The static magnetic field from the permanent, and eddy current inside the steel pipe are generated the vibration in the steel pipe. And the thickness of the hot spring scale is evaluated from this vibration intensity. It is shown that the thickness of hot spring scale from 0 mm to 15 mm can be inspected by this proposed method. In addition, the proposed inspection principle of this inspection method will be clarified by 3-D electromagnetic force analysis and displacement analysis. Show more

Keywords: Hot spring scale, electromagnetic force, electromagnetism vibration, steel material, electromagnetic 3-D FEM, displacement 3-D FEM

DOI: 10.3233/JAE-220207

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S483-S491, 2023

Authors: Diao, Chengwu | Zhao, Wenliang | Li, Min | Chen, Dezhi | Sun, Youliang

Article Type: Research Article

Abstract: This paper deals with the leakage magnetic field calculation and magnetic field shielding design of transformers. A large-capacity traction transformer is firstly established, and its magnetic flux density and eddy current loss of the transformer tank are calculated by the layered subdivision method and the surface impedance method. To reduce the eddy current loss of the tank, plate-shaped magnetic shielding and electromagnetic shielding are installed on the surface of the tank. And the simulation results show that plate-shaped magnetic shielding has better shielding effectiveness compared with electromagnetic shielding. Then based on the plate-shaped magnetic shielding, the tile-shaped magnetic shielding is …proposed to further reduce the magnetic flux density and loss of the tank. By analyzing the shielding effect of tile-shaped shielding at different heights and widths, the tile-shaped shielding structure with the best shielding effect is obtained. Finally, the advantages of tile-shaped shielding are verified by magnetic-thermal coupling analysis. Show more

Keywords: Traction transformer, layered subdivision, surface impedance method, magnetic shielding

DOI: 10.3233/JAE-220208

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S493-S507, 2023

Authors: Diao, Chengwu | Zhao, Wenliang | Li, Min | An, Ningning

Article Type: Research Article

Abstract: The open-winding permanent magnet synchronous motor (OWPMSM) system is a novel high-cost system that uses dual-inverters to control both sides of the stator to improve the performance of the motor. To save the system cost, the three-phase four-switch open-winding permanent magnet synchronous motor (TPFS-OWPMSM) system is proposed to replace the general three-phase six-switch OWPMSM system, but it brings the problem of bridge arm capacitor voltage offset. To solve the instability problem caused by capacitance, this paper carries out the state analysis and offset source analysis of the inverter capacitor voltage, and proposes a dual-inverters capacitor voltage balance control strategy. The …capacitor balance control converts unstable capacitor offset voltage into current and injects the currents into the stator current loop through closed-loop correction. And this strategy includes the optimal control of different capacitors under dual-inverters with the goal of system stability. The effectiveness of the balancing strategy is verified by the simulation of various motor working conditions. Show more

Keywords: Three-phase four-switch, open-winding permanent magnet synchronous motor, capacitor voltage offset, capacitance balance control

DOI: 10.3233/JAE-220209

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S509-S519, 2023

Authors: Deng, Jie | Pei, Cuixiang | Zhang, Yuange | Liu, Tianhao | Chen, Hong-En | Chen, Zhenmao

Article Type: Research Article

Abstract: Visualization of surface wave based on signal and imaging processing schemes is an efficient way to enhance the detectability of ultrasonic testing for inspection of surface or near surface small defect in layered structures such as the thermal barrier coating (TBC) system. A full wave field measurement is necessary to get information for visualization of the ultrasonic wave. In this paper, a non-contact, array pickup electromagnetic acoustic transducer (EMAT) with 32 receiving coils and a phased array EMAT system are developed for efficient measurement of full information of surface wave field. Based on the multiple channel EMAT signals at different …scanning position, a dynamic visualization algorithm is developed to image the propagation, reflection and scattering wave caused by defect and structure edges. The validities of the array pickup EMAT and the dynamic visualization algorithm are demonstrated by using both simulated and measured surface wave signals for a prototype array EMAT and an aluminum plate with small hole defect. Show more

Keywords: Array EMAT, pickup coils, full wave field measurement, dynamic wave visualization

DOI: 10.3233/JAE-220210

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S521-S530, 2023

Authors: Wang, Ning | Zhao, Wenliang | Li, Min | An, Ningning

Article Type: Research Article

Abstract: This paper deals with the design and analysis of a surface-mounted outer rotor in-wheel motor (IWM) with the aim of reducing cogging torque and torque ripple for electric vehicles. The proposed IWM is equipped with axial sinusoidal surface-mounted permanent magnets (PMs), with the purpose of producing sinusoidal air gap flux density distribution, thus to realize sinusoidal back electromotive force (EMF) and smooth electromagnetic torque. To highlight the advantage of the proposed IWM, the conventional IWM with tile-shaped PMs and the IWM with stepwise-shaped PMs are also studied for comparison. The finite element method in the commercial software package is utilized …to analyze the performance of the three motors, including the radial flux density of air gap, back EMF, cogging torque, and electromagnetic torque. Through the quantitative comparison, it is found that the proposed IWM greatly reduces the cogging torque, highly improves the sinusoidality of back EMF, and nearly eliminates the torque ripple. Show more

Keywords: In-wheel motor, sinusoidal permanent magnet, air gap flux density, cogging torque, torque ripple

DOI: 10.3233/JAE-220211

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S531-S540, 2023

Authors: Zhang, Yuange | Pei, Cuixiang | Deng, Jie | Liu, Tianhao | Jiang, Peng | Chen, Hong-En | Chen, Zhenmao

Article Type: Research Article

Abstract: In this paper, a novel Phased Array fully Flexible Rayleigh-wave EMAT (PAFR-EMAT) suitable for inspection of curved surface based on flexible coil bias field magnet EMAT is proposed. The PAFR-EMAT consists of a flexible racetrack coil generating long pulsed bias magnetic field instead of the conventional permanent magnets, and flexible meander coils triggered in sequence to induce transient eddy current for exciting enhanced Rayleigh wave of MHz frequency. Based on the Lorentz force mechanism, pulsed electromagnetic fields and the generated ultrasonic waves of the proposed new EMAT are studied through numerical simulation at first. Experiments are conducted then to check …the practical performance of the PAFR-EMAT for pipe inspection. Results show that the PAFR-EMAT has good performance in Rayleigh wave generation for inspection of the curved surface of metallic pipe and is capable to detect surface crack of small depth. Show more

Keywords: EMAT, flexible transducer, Rayleigh wave, nondestructive testing

DOI: 10.3233/JAE-220212

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S541-S549, 2023

Authors: Kitayama, Fumiya | Kondo, Ryou | Endo, Riku

Article Type: Research Article

Abstract: Lower limb exoskeletons with actuators aids disabled individuals in walking. However, the exoskeleton weight is greater than that of conventional medical devices such as orthoses and walking frames. In this study, we propose a novel strain wave gear for light exoskeletons, which is 50% lighter than conventional commercial strain wave gears. This gear uses magnets and yokes, rather than mechanical elements. The thin-walled elastic cylinder is deformed by the magnetic force in the gear, and the torque is transmitted by tooth engagements. The maximum torque was calculated to be 10.5 Nm using flexible multibody dynamics analyses with a magnetic force database. …The outcome was efficient in development of lightweight machines. Show more

Keywords: Strain wave gear, magnetic force, lower limb exoskeletons, electromagnetic analysis, multi body dynamics analysis

DOI: 10.3233/JAE-220213

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S551-S560, 2023

Authors: Huang, YinHui | Wang, MingHui | Yu, HongLiu

Article Type: Research Article

Abstract: The prosthetic socket is the key part connecting the prosthesis and the stump. It needs to be functional, safe, and comfortable at the same time. However, the volume fluctuation of the stump causes the incompatibility between the stump and the socket. This paper designs an adaptive prosthetic socket with rope-driven to fit stump volume fluctuation. The designed adaptive prosthetic socket with constant force characteristic using superelastic shape memory alloy may solve the problem of uneven pressure on the stump due to stump volume fluctuation and adapt stump volume. To obtain a good constant force range, the constant force characteristic of …the socket is optimized and validated by finite element analysis. The experimental results show that the constant force mechanism using the C-shaped shape memory alloy sheets can obtain good constant force characteristics, and the socket can apply a constant force to the stump to solve the problem of uneven pressure distribution between the stump and the socket. Show more

Keywords: Prosthetic socket, constant force, stump, volume fluctuation, shape memory alloy

DOI: 10.3233/JAE-220219

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S561-S569, 2023