International Journal of Applied Electromagnetics and Mechanics - Volume 71, issue 4

Authors: Li, Zheng | Wei, Xiaopeng | Liu, Libo | Wang, Xueting | Liu, Mengjie | Guo, Xiaoqiang | Sun, Hexu

Article Type: Research Article

Abstract: The Deflectable double-stator Switched Reluctance Generator (DSRG) has the advantages of simple structure, small volume and multi-dimensional operation. The DSRG and propeller are combined into the application of underwater power generation. With the help of the deflect ability of the generator, the efficiency is improved. Due to the uncertainty of ocean current direction and the structure of switched reluctance generator, the torque ripple is one of the important factors damaging the underwater generator. In order to effectively suppress the influence of torque ripple caused by generator operation, a method of adding pole shoes on the pole side of outer stator …is proposed, so as to reduce the torque ripple. The propulsion structure running at different deflection angles is simulated. The torque and speed obtained before and after pole shoe optimization are input into the propeller model. The pressure and speed characteristics of the corresponding blade structure are simulated to verify the effect of optimization and the effectiveness of the power generation system. Show more

Keywords: Double stator, finite element analysis, switched reluctance motor, torque ripple

DOI: 10.3233/JAE-220020

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 305-324, 2023

Authors: Zhou, Deqiang | Jiao, Tianqi | Gao, Xue | Zhou, Runtao | Sheng, Weifeng

Article Type: Research Article

Abstract: Since Remote field eddy current (RFEC) detection technology is barely limited by the skin effect, it can realize the defect detection of large-thickness components. Whereas, the structure of the RFEC probe for the planar conductor is complicated, resulting in an oversized probe. This hinders the application and development of the RFEC testing technology. In this paper, finite element simulations and experimental verification are used to optimize the RFEC probe structure for flat conductors. The results have shown that the thickness of the magnetic shield is the dominant factor in achieving high performance of RFEC inspection of flat conductors. When inspecting …both ferromagnetic and non-ferromagnetic flat conductors, cylindrical magnetic shields with appropriate thickness and appropriate excitation frequencies are preferred for improvement of RFEC testing. Show more

Keywords: Magnetic shielding, RFEC, energy flow analysis, nondestructive testing

DOI: 10.3233/JAE-220089

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 325-339, 2023

Authors: Zuo, Fuliang | Su, Sanqing | Wang, Wei | Deng, Ruize | Liu, Xinwei | Li, Junting

Article Type: Research Article

Abstract: Metal magnetic memory testing (MMMT) is a nondestructive testing technique that can detect early signs of damage in components. Many scholars have studied the effect of uniform stress on the self-leakage magnetic field (SLMF) strength of ferromagnetic materials. However, there is still insufficient research on the stress concentration caused by uneven stress, under the combined action of bending and shear. In this study, we studied the law of distribution of the magnetic signal, H P (y ) and magnetic gradient, K , on a part of the surface of a steel box girder damaged by buckling, using a four-point …bending pattern. The results showed that combining the three peak positions, namely, the magnetic signal, its newly added comparing initial magnetic signal, and magnetic gradient distribution curves, could accurately determine all stress concentration positions on the flange of the steel box girder, and reduce the interference of the initial complex residual magnetic field. Furthermore, we studied the quantitative relationship between normal stress, shear stress, and a magnetic signal. It was found that the stress-magnetic relationship conformed to the Jiles–Atherton model. The peak value of H P (y ) – 𝜎, |H P (y )|a – 𝜎 , and K max – 𝜎 relationship curves could be used as the characteristic point of the critical yield stress at the action of normal and shear stress. The degree of stress concentration of the flange and web could be quantitatively evaluated by fitting the K max – 𝜎 relationship. This study can provide an experimental reference for the application of MMMT in the evaluation and early warning of the state of damage to a steel box girder. Show more

Keywords: Metal magnetic memory testing (MMMT), steel box girder, stress-magnetic relationship, yield limit, magnetic characteristic parameters

DOI: 10.3233/JAE-220057

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 341-361, 2023

Authors: Chen, Xiaoyu | Leng, Yonggang | Sun, Fei | Su, Xukun | Sun, Shuailing | Xu, Junjie

Article Type: Research Article

Abstract: A novel Triple-magnet Magnetic Dynamic Vibration Absorber (TMDVA) with Eddy Current Damping (ECD) and Coulomb damping is proposed in this paper. A multi-storey structure is selected as the vibration reduction object. First, the equivalent dynamics model of the TMDVA multi-storey structure vibration reduction system is established. Then the nonlinear magnetic force model is built according to the magnetizing current theory. Next, an ECD accurate calculation model is developed and derived based on Faraday’s law of electromagnetic induction. Because of the model, the ECD coefficient can be designed and adjusted arbitrarily. The full text indicates that adjusting the ECD coefficient properly …can not only improve the vibration reduction effect of the TMDVA, but also reduce the sensitivity of the vibration reduction effect to the excitation amplitude as well as enhance the broadband vibration reduction performance and the robustness of the TMDVA. With its simple structure, the TMDVA is easy to be implemented and miniaturized. And the low frequency vibration reduction effect of the TMDVA is better than other existing magnetic dynamic vibration absorbers. Taken together, the TMDVA has potential application value in passive vibration reduction of engineering structures. Show more

Keywords: Triple-magnet magnetic dynamic vibration absorber, eddy current damping, passive vibration reduction, multi-storey structure

DOI: 10.3233/JAE-220128

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 363-388, 2023

Authors: Zhou, Feng | Li, Xiaobo | Tong, Xin | Hu, Heng | Jiang, Peng

Article Type: Research Article

Abstract: Aiming at the problems existing in current electric energy replacement, such as the random energy fluctuation of the power grid, the energy storage of the power grid and the consumption of new energy, electromagnetic coupling heating technology and methods based on power frequency high power is proposed. According to the theory of electromagnetic induction heating, Maxwell’s equations are used to establish a three-dimensional electromagnetic field simulation model, determining the size of the core and the windings, and completing the structural design of the heater. Based on the simulation model of electromagnetic coupling heater, the back electromotive force of the primary …winding, the induced current of the secondary winding, the B–H curve field diagram of the core, and the J-field diagram of the secondary winding are analyzed to explore heating efficiency of the heater and verify the correctness of electromagnetic coupling heating mechanism. The relationship between the coupling gap, the number of heat dissipation rings, and the air gap and heating efficiency of the heater was further explored, and the model structure of the heater was optimized according to the variation rules so that heating efficiency of the heater reached more than 99%. The electromagnetic coupling heater achieves high efficiency, cleanliness and low carbon, and power frequency high power, which is of great significance to the renewal of electric heater in the future. Show more

Keywords: Electromagnetic induction heating, high power, power frequency, the coupling gap, heat dissipation ring, the air gap

DOI: 10.3233/JAE-220136

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 389-412, 2023

Authors: Ronggui, Song | Guoming, Gao | Xin, Wang | Shunxi, Lou | Wei, Wang | Zanquan, Pu

Article Type: Research Article

Abstract: In the service of antenna arrays, especially for the large-scale antenna arrays, the deformation of the antenna structure is inevitable due to the influence of many structural factors. Therefore, effective compensation for the electrical performance of the antenna is one of the important means to ensure its normal and stable operation. An electrical compensation method based on the genetic algorithm to change the phase of the radiating element is proposed, which also considers the quantization error of the phase shifter. Under the 0.46𝜆 deformation condition, the left side lobe level of the horizontal radiometer with the worst performance deterioration is …compensated by 2.15 dB, reaching the ideal state before deformation. The objectives and constraints in the optimization model can be adjusted according to the actual work requirements. The correctness and feasibility of proposed method are verified by an antenna array with 8 × 32 radiating elements. Show more

Keywords: Antenna arrays, electrical compensation, quantization error, genetic algorithm

DOI: 10.3233/JAE-220122

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. 4, pp. 413-425, 2023