International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Ma, Yangyang | Li, Yongjian | Chen, Ruiying | Yue, Shuaichao | Sun, He

Article Type: Research Article

Abstract: With the increase in power electronic equipment in power system, the excitation of ferromagnetic materials often involves a large number of harmonics. Therefore, it is necessary to construct an accurate dynamic hysteresis model to adapt to this complicated operating state of electrical equipment. In this paper, a Hybrid Dynamic Hysteresis Model (HDHM), which can effectively characterize the harmonic excitation of materials is studied based on the Preisach model and Stacked Auto-Encoder (SAE) model. The static part of this model takes the form of the inverse Preisach model. And the Multiple Dynamic Hysteresis Model Set (MDHMS) is constructed by multiple dynamic …models of eddy currents and excess characteristics of the ferromagnetic materials. The dynamic part of the HDHM takes the form of the model structure combining the Stacked Auto-encoder and the MDHMS. The calculation results of the hysteresis loop and ferromagnetic loss in the harmonic condition of silicon steel sheet proves the validity of this model. Moreover, compared with the conventional dynamic hysteresis model, the HDHM has better accuracy and generalization ability. Show more

Keywords: Hybrid dynamic hysteresis model, the Preisach model, multiple-model set theory, ferromagnetic materials, iron loss

DOI: 10.3233/JAE-220112

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2022

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. Pre-press, no. Pre-press, pp. 1-24, 2022

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. Pre-press, no. Pre-press, pp. 1-26, 2022

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. Pre-press, no. Pre-press, pp. 1-21, 2022

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. Pre-press, no. Pre-press, pp. 1-20, 2022

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. Pre-press, no. Pre-press, pp. 1-15, 2022

Authors: Ouili, Mehdi | Mehasni, Rabia | Feliachi, Mouloud | Latreche, Mohamed El Hadi

Article Type: Review Article

Abstract: In this work, an identification of the electrical conductivity of material 𝜎 was carried out. This is accomplished by formulating and solving an inverse problem based on the minimization of an objective function using the Particle Swarm Optimization (PSO) method. Such a function represents the difference between the experimentally measured final ejection position and that numerically computed by solving the material magnetic separation problem. For this, the coupled magnetic field and the material dynamic governing equations were numerically solved using the finite element (FE) and Runge–Kutta (RK4) methods. The strong correlation observed between the computed and measured final position of …the separated material verifies the accuracy of the proposed identifying approach. Show more

Keywords: Electrical conductivity, finite element, identification, inverse problem, magnetic separation, particle swarm optimization

DOI: 10.3233/JAE-220248

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-12, 2023

Authors: Li, Zequn | Li, Desheng | Guo, Benzhen | Zhao, Tong

Article Type: Research Article

Abstract: This paper proposes an electromagnetic damping generator (EDG), which is a novel downhole generator for the rotary steerable system (RSS). The EDG is designed to solve the problem of unstable voltage output by the RSS generator. The generator is designed by integrating a traditional generator and an eddy current retarder (ECR). The system converts the excess kinetic energy of the EDG rotor into heating energy by the principle of eddy-current braking and resistance heating. The electromagnetic finite element models of the generator part and ECR part are established and solved by computer. The voltage and torque generated by the generator …part and the braking torque of the ECR part are predicted. In the bench test, When the input power is 2537 W < P input < 3304 W, the EDG is able to output 300.8 V. When the input power is 3304 W, the output voltage of the ordinary generator is 346 V. The EDG can be adjusted by a decrement of up to 45.2 V to output the rated voltage. The problem of generator output voltage instability in the RSS is solved when mud flow is unstable. Show more

Keywords: Generator, ECR, torque, power, voltage

DOI: 10.3233/JAE-220256

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2023

Authors: Wang, Hujun | Gao, Zhongquan | Meng, Yuan | Li, Yan | Zhang, Qiang

Article Type: Research Article

Abstract: When the ferrofluid is used to seal liquid, the relative movement between the ferrofluid and the sealed liquid causes the stability problem of their interface, and the sealing performance is poor. However, the spiral and the spiral sleeve of the spiral labyrinth seal interact with the sealed liquid to make it reverse flow to prevent leakage when the shaft rotates. In order to improve the performance of rotary ferrofluid seal, the ferrofluid-spiral combined seal structure and the ferrofluid-spiral labyrinth combined seal structure are designed. A combined seal test-bench is built. The pressure resistance experiments and seal life experiments of ferrofluid …seal and two type of combined seals are carried out. The theoretical and experimental results show that the sealing performance of the ferrofluid-spiral labyrinth combined seal is better than that of the ferrofluid-spiral combined seal ferrofluid seal. Ferrofluid-spiral labyrinth combined seal can not only solve the failure problem of ferrofluid seal at high speed, but also solve the leakage problem of spiral seal at shutdown and low speed, so as to achieve a more stable sealing effect at different speeds. The higher the speed is, the better its sealing performance is. Show more

Keywords: Ferrofluid seal, spiral labyrinth seal, combined seal, pressure resistance, seal life

DOI: 10.3233/JAE-220228

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2023

Authors: Wang, Huanmin | Chen, Jing | Yuan, Xunfeng | Chen, Yao | Zhang, Hui

Article Type: Research Article

Abstract: Electric vehicle (EV) wireless charging technology has recently attracted a lot of attention and has a broad potential for commercial application development. A fundamental performance indicator of wireless charging systems is efficient transmission. Magnetic coupling mechanism design and circuit parameters have the greatest effects on the transmission efficiency of the system. In this study, the output power and efficiency of the wireless power transfer (WPT) circuit were theoretically computed based on the LCC-type resonant network. Simulation studies demonstrate that the transmission efficiency and output gain deviate significantly from the expected value when circuit parameters are changed. To improve transmission efficiency, …the optimal impedance configuration was created using a semi-controlled rectifier circuit. Based on electromagnetic field theory and equivalent magnetic circuit model, a new contactless transformer structure was optimized and created, and the new contactless transformer had a higher coupling coefficient. The coil offset had a greater impact on the transmission efficiency. The results indicate that within a certain distance, the coupling coil offset had no impact on transmission efficiency, and beyond that distance, the transmission efficiency was almost non-existent. Both the feasibility of the practical verification and the accuracy of the theoretical study were tested using a low-power wireless charging experimental setup. This paper provides design guidelines for wireless charging systems using circuit parameter sensitivity analysis and contactless transformer optimization design. Show more

Keywords: Wireless charging, parameter sensitivity, contactless transformer, electric vehicle

DOI: 10.3233/JAE-220084

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-18, 2023