International Journal of Applied Electromagnetics and Mechanics - Volume 65, issue 1

Authors: Liu, Jinhui | Meng, Dawei | Ai, Mengmeng | Wang, Xiaohui

Article Type: Research Article

Abstract: A method to analytically calculate the parameters of the fault area between core laminations are proposed and the dynamic trend of the fault development is predicted to comprehensively and accurately obtain the fault degree and damage level of short-circuits between the core laminations of large motors. Considering the influences of frequency and magnetic flux on the axial skin depth of the core and of the eddy current loss on the insulation resistance between the laminations and reviewing the laminations of the stator core tooth as the research object, based on the Maxwell equations and equivalent circuit theory, analytic expressions of …active power and induced voltage in the fault area between the laminations are derived; the influence of the number of fault laminations on the electrical parameters in the fault area is quantitatively analyzed; the actual fault development process of the short-circuit faults between the laminations are obtained; and the correctness and effectiveness of the proposed method are verified via numerical simulations and the experiment of faults between core laminations. The sequence of induced voltage changing with the number of fault laminations is selected as the grey sequence to establish the grey prediction model (GM (1,1)). The development curve of the damage depth of the faults between core laminations along the axial direction is illustrated by calculating the sequence data. The results show that the error between the predicted value of the damage depth of the short-circuit fault herein and the experimental value is less than 7%. This method can be used in engineering practices. Show more

Keywords: Faults between core laminations, analytic method, eddy loss, damage depth, GM (1,1)

DOI: 10.3233/JAE-190165

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 1-16, 2021

Authors: Kawaguchi, Hideki

Article Type: Research Article

Abstract: This paper proposes a scattered field formulation of the finite-difference time domain method (S-FDTD) combining with a time-domain electric field integral equation (TD-EFIE) based on surface equivalence theorem. The scattered field formulation enables us to reduce computation cost effectively for the case that scatterers are located at a far distance from field sources of electromagnetic wave since we need to calculate the scattered field component only on the region in the vicinity of the scatterers. Then it is required for the use of the scattered field formulation that the field source for the incident field component has to be expressed …by any analytical solutions such as a point dipole source, plane wave, and so on. In this work, the scattered field formulation of the FDTD method is applied to cases that there are no analytical expressions of the field sources, in which the field source contains conductors such as antennas, combining with the TD-EFIE on a virtual surface which encloses the field sources. Then, it is known that calculation of the TD-EFIE itself is time consuming. This paper considers speed-up of the S-FDTD simulation based on the TD-EFIE using a spherical harmonic expansion of Green’s function of Helmholtz equation, additionally. Show more

Keywords: Finite-difference time-domain method, microwave propagation, scattered field formulation, surface equivalence theorem, time-domain electric field integral equation, spherical harmonic expansion, Green’s function of Helmholtz equation

DOI: 10.3233/JAE-190164

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 17-25, 2021

Authors: Guo, Liang | Chen, Liang | Galea, Michael

Article Type: Research Article

Abstract: This paper presents a multiphysics modeling and design methodology for high speed permanent magnet synchronous motors (PMSM) for electric traction applications. In this proposed methodology, the electromagnetic, thermal and mechanical fields are coupled together. The electromagnetic model is used to analyze the electromagnetic performances and losses of the PMSM, which then feed the thermal and mechanical models. The thermal model focuses on the machine’s temperature rise while the mechanical model is used to analyze the stress distribution of the PMSM. Combined together, a powerful multiphysics model aimed for the design of high speed PMSMs is achieved. The design results prove …that the designed PMSM can simultaneously meet the requirements of high power density, high temperature and high reliability. Show more

Keywords: Multiphysics modeling, permanent magnet synchronous motor, high speed

DOI: 10.3233/JAE-200019

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 27-43, 2021

Authors: Zhou, Dong | Wei, Minxiang | Shi, Lihua | Cao, Jie | Su, Liyuan

Article Type: Research Article

Abstract: In this paper, the fuel electronic control system of the engine as an engine control process is designed and constructed to provide the fuel adjustment function of the aero-engine. Then, the electromagnetic pulse (EMP) experiment is established by exposing it to electromagnetic field pulses of the bounded-wave simulator. Now, the damage threshold is also determined. At the same time, the induced differential voltage and common current signals are measured through the printed circuit board (PCB) port, which is necessary to cause a specific microprocessor to fail. The wavelet transform is employed to establish a time-frequency method to process the induced …voltage signal. The susceptible frequency areas and coupling energy distribution are applied to the speed acquisition system. Their characteristics are employed to propose a new electromagnetic interference decrease method in both time and frequency domain. This method could be considered as a useful tool for studying the electromagnetic pulse coupling interference. Show more

Keywords: Fuel electronic control system, electromagnetic pulse (EMP), time-frequency method, electromagnetic interference (EMI), interference decrease

DOI: 10.3233/JAE-190161

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 45-57, 2021

Authors: Yang, Qing | Wang, Junnan | Hu, Zhu | Ni, Zhonghua | Lu, Rongsheng | Yi, Hong

Article Type: Research Article

Abstract: In this paper, a new portable, low-cost magnet with a good homogeneity is presented. The single-layer central magnet structure based on Halbach-type array has been designed, simulated which can generate a magnetic field of 1 T under the weight of 2 kg. Magnetic strips placed at the ends of the central magnet are presented to improve the central homogeneity. In order to counteract the inhomogeneity resulting from manufacturing tolerances, a new compact shimming structure designed for miniature Halbach magnet is applied. With this structure a reduction of the full width at half maximum (FWHM) from 21 kHz to less than …only 0.7 kHz, which is adequate for achieving a good NMR relaxation signal. This novel miniature magnet structure has achieved an excellent balance between cost and homogeneity for portable time domain NMR. Show more

Keywords: Halbach magnet, passive shimming, linear programming, portable NMR, FEM simulations

DOI: 10.3233/JAE-200001

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 59-73, 2021

Authors: Li, Xiangchao | Luo, Hua | Chu, Lei | Ouyang, Wen | Wen, Qiaoli

Article Type: Research Article

Abstract: Aiming at the problem of the corona discharge trigger electric filed threshold at different shapes of a metal tip, through the theoretical analysis of the electric field distribution near the surface of the conical tip and the ellipsoidal tip, and the laboratory simulation experiment, reached the following conclusion. The relationship between the value of corona current amplitude, the frequency and the tip’s radius of curvature is obtained; the corona discharge electric field threshold is relatively fixed and between 6.9382 kV/cm and 8.2824 kV/cm. The above relationship has a certain reference value in practical application and computer simulation.

Keywords: Corona discharge, finite element, electric field threshold, corona current

DOI: 10.3233/JAE-190160

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 75-90, 2021

Authors: Tang, Bin | Lin, Ziyan | Jiang, Haobin | Yin, Yue

Article Type: Research Article

Abstract: Permanent magnet slip coupling (PMSC) is a kind of contactless transmission device with the advantages of clutch function, continuous speed regulation and no mechanical wear. The PMSC was introduced into the hydraulic power steering system (HPS) to regulate the steering pump speed so as to improve the steering stability and reduce the energy consumption. To evaluate the designed PMSC electromagnetic characteristics and dynamic characteristics of the PMSC were investigated and verified. Two-dimensional finite element model of the PMSC was built to investigate the electromagnetic characteristics. The simulation results of induced electromotive force, induced current and electromagnetic torque demonstrated that the …PMSC had excellent electromagnetic characteristics. The speed regulation circuit of the PMSC was developed to investigate the dynamic characteristics. The results indicated that the PMSC had excellent dynamic characteristics under the condition of high load, inferior dynamic characteristics under the condition of low load. The bench tests were carried out to verify electromagnetic characteristics and dynamic characteristics of the PMSC. It can be seen that the test results of the induced electromotive force and output speed of the PMSC were in consistent with the simulation results. The real vehicle tests were conducted and the results demonstrated that the permanent magnet coupling based electronically controlled hydraulic power steering system (P-ECHPS) greatly improved low-speed steering maneuverability and high-speed steering stability of heavy-duty vehicles. Show more

Keywords: Permanent magnet slip coupling, electromagnetic characteristics, dynamic characteristics, hydraulic power steering, speed regulation circuit

DOI: 10.3233/JAE-190122

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 91-107, 2021

Authors: Li, Tao | Zhang, Youtong | Liang, Yuxiu | Yang, Ye | Jiao, Jie

Article Type: Research Article

Abstract: In order to solve the contradiction between the opening and closing time of the high speed on/off valve for space propulsion systems of the liquid rocket engine, a pneumatic pilot-operated high speed on/off valve is proposed and multiobjective optimization for the opening and closing time of the valve is carried out in this paper. Based on the analysis of the working mechanism of the valve, the mathematical models for the pilot valve and the main valves are established respectively. The Plackett-Burman design is used to select the optimization variables which influence the performance of the response time significantly. The central …composite design is used to obtain the sample points and establish second-order response surface models of the response time. The NSGA-II is used to obtain the Pareto front of the optimization objectives. The optimized opening and closing time can be reduced by 17.7% and 37.4% respectively. A prototype based on the optimized parameters is manufactured and tested to verify the accuracy of the multiobjective optimization results. The test results verify the validity of the optimization approach for the proposed valve in this paper. Show more

Keywords: Multiobjective optimization, pneumatic pilot-operated high speed on/off valve, response surface model, response time, solenoid valve

DOI: 10.3233/JAE-190074

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 109-127, 2021

Authors: Sitheswaran, Bhuvaneswari | Pandarinathan, Sivaraman | Alagu, Matheswaran | Ponnusamy, Prem

Article Type: Research Article

Abstract: India has enormous wind potential and average wind velocity is about 6 m/s, whereas the conventional wind turbine mechanism is operated at 7 m/s–12.5 m/s. It is necessary to design low speed wind energy conversion to harvest the electrical energy from wind. Mostly, Radial flux permanent magnet generator (RFPMG) is used for low speed wind turbine applications. This Conventional RFPMG has the drawbacks of low flux density and increase in weight due to large number of poles accommodation. In order to overcome the above setbacks, this paper proposes a double sided coreless axial flux permanent magnet generator (AFPMG) for low …speed wind energy conversion applications. The performance analysis of the proposed AFPMG is carried out through finite element method using ANSYS Maxwell software. Finally the performance of RFPMG and AFPMG is compared based on the flux linkage, flux density, induced emf, stator current, moving torque, cogging torque, Total Harmonic Distortion (THD), material consumption, losses and efficiency. It is evident from the results that AFPMG gives the better performance than RFPMG in all such aspects. Show more

Keywords: Radial flux, axial flux, direct drive, ANSYS Maxwell, finite element analysis

DOI: 10.3233/JAE-190150

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 129-147, 2021

Authors: Sarker, Mahidur R. | Mohamed, Ramizi | Saad, Mohamad Hanif Md | Tahir, Muhammad | Hussain, Aini

Article Type: Research Article

Abstract: Nowadays most of the time humans spend in daily life on mobile phones but the thing that tends to get worried about is battery consumption as they run out quickly. We could not make important jobs such as emergency calls or send important documents when our phone battery runs out. This study represents vibration based sound energy is harvested to charge mobile phones using six piezoelectric sound transducers (PSTs) which converts sound energy to electrical energy. This paper proposed designing a low voltage sound energy harvesting circuit (SEHC) using PSTs. PSTs with SEHC is considered as an alternative power source …to charge the smart phone battery, especially for remote area where power is unavailable. The SEHC consists of PSTs, non-controlled bridge rectifier circuit, filter, switch-mode open loop boost converter, charger circuit, and storage device at the output terminal. The complete SEHC has designed and simulated using Matlab Simulink software. The PSTs have been analyzed with different frequency and the output voltage of PSTs utilized as an input source to design SEHC. Finally, the results are generated at an output of 7.8 V DC from an input 1.05 V AC at 314 Hz through a SEHC using the PSTs, which suitable to charge smartphone battery efficiently. Show more

Keywords: Energy harvesting, piezoelectric sound transducer, vibration, converter

DOI: 10.3233/JAE-190121

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 149-169, 2021

Authors: Shi, Minxia | He, Cong | Zhang, Xuanrui | Qiu, Aici | Li, Junhao

Article Type: Research Article

Abstract: This paper enhanced the integration-type E&S model and the dynamic E&S model for integrating the impact of DC-biased field and eddy current on vector magnetic properties of electrical steel sheet. B and H of electrical steel sheet are measured under DC-biased and rotating fields. Based on the measured results, the databases of reluctivity and hysteresis coefficients of both the enhanced integration-type E&S model and the improved dynamic E&S model are established for predicting H waveform under any given operating condition. By comparing the H waveform calculated by the …enhanced integration-type E&S model and the improved dynamic E&S model with the experimental H waveform, it is found that both two models have good reliability and the improved dynamic E&S model has slightly better accuracy than the enhanced integration-type E&S model. Show more

Keywords: Electrical steel sheet, DC-biased magnetization, Eddy current, the E&S model

DOI: 10.3233/JAE-190095

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 171-179, 2021

Authors: Shi, Wenze | Chen, Weiwei | Lu, Chao | Cheng, Jinjie | Chen, Yao

Article Type: Research Article

Abstract: The interest in applying non-destructive testing to the examination of the flaw and measurement of the thickness in the metals at high temperatures is increasing as the metal processing becomes continuous. Based on this background, we designed a water-cooled shear wave Electromagnetic Acoustic Transducer (EMAT) with a surface cooling technique, and the conversion efficiency could be improved by surface cooling. We used the chirp pulse compression technique to process the raw ultrasonic wave signal without synchronous average. Besides, a large casting slab with coarse grains and a massive forging with high temperatures were chosen as the testing objects. Then, the …effect of the lift-off distance on the Signal-to-Noise Ratio (SNR) of ultrasonic signals from the EMATs operated in both the pulse-echo mode and pitch-catch mode was investigated. Subsequently, the ultrasonic signals were de-noised respectively by synchronous averages and pulse compression, and the noise reduction ability was compared. Finally, the EMAT was tested with the forging at different temperatures from 92 °C to 730 °C. The performance of the EMAT with the excitation of a tone-burst signal was also compared with the performance of the EMAT using pulse compression technique. Results show that the lift-off, SNR, range resolution, and inspection efficiency can be largely enhanced with the signal processing of chirp pulse compression to the ultrasonic wave signal with no synchronous averaging. When the forging’s temperature is 730 °C, the SNR of the compressed signal is comparable to the SNR of the signal processed with 64 synchronous averages, and the wave-packet duration can be reduced by 80.5%. The proposed EMAT detection technique is particularly suited for real-time measurement and high-temperature testing. Show more

Keywords: EMAT, pulse compression, lift-off, high-temperature testing, real-time measurement

DOI: 10.3233/JAE-201531

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 65, no. 1, pp. 181-196, 2021