International Journal of Applied Electromagnetics and Mechanics - Volume 74, issue 3

Authors: Yang, Panpan | Li, Jianwei | Zhang, Leian | Mu, Zonggao | Li, Zixuan | Wang, Jianhong

Article Type: Research Article

Abstract: This paper proposes a low-cost approach to determine the optimum Conductor Plate (CP) thickness without needs for mathematical models and large data volumes, which means that 0.6 times of the Standard Depth of Penetration (SDoP) can be directly selected as the optimum CP thickness without calculation. Firstly, the SDoP is introduced. Then, the influences of speed and conductivity on the optimum CP thickness are investigated. Finally, the relationship between the SDoP and the optimum CP thickness is found. The optimum CP thickness can be selected directly according to the relationship without mathematical models and large data volumes. It not only …guarantees high braking force, but also reduces the weight of the LPMECBs as much as possible. Show more

Keywords: Low-cost approach, conductor plate thickness, standard depth of penetration, permanent magnet, eddy current brake

DOI: 10.3233/JAE-220292

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 3, pp. 195-207, 2024

Authors: Zhang, Wendong | Pang, Liang | Hu, Huoda | Qin, Haihong | Zhao, Chaohui

Article Type: Research Article

Abstract: To study the influence of the magnitude of the excitation current on the radial electromagnetic force wave of the tangential magnetizing parallel structure hybrid excitation synchronous motor (TMPS-HESM) under different working conditions. Firstly, the basic structure of the motor and the rotor magnetic circuit model is introduced. Secondly, considering the influence of excitation current, the Maxwell stress tensor method is used to analyze the radial electromagnetic force wave of the motor and the source, frequency and order of the radial electromagnetic force wave that has a great influence on the electromagnetic vibration of the motor are qualitatively obtained. Then, the …three-dimensional finite element method is used to calculate the variation law of the radial electromagnetic force wave when different excitation currents are applied under no-load and load conditions, revealing that the DC excitation will increase the amplitude of the radial electromagnetic force wave of a specific order. Meanwhile, the influence of load torque variation on the radial electromagnetic force wave is discussed, and it is found that the (2f , 8) and (6f , 24) order electromagnetic force waves are greatly affected by the armature reaction. The work provides a theoretical basis for further suppressing the electromagnetic vibration of this type of hybrid excitation motor. Show more

Keywords: Hybrid excitation motor, radial electromagnetic force wave, excitation current, analytical method, finite element method

DOI: 10.3233/JAE-230016

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 3, pp. 209-233, 2024

Authors: Hussain, Iftikhar | Woo, Dong-Kyun

Article Type: Research Article

Abstract: Mutual inductance is one of the main parameters required to determine the power link’s performance (output voltage, efficiency) in wireless power transfer. The coils are often misaligned angularly in these applications, which affects the mutual inductance and thus the performance. Hence, an accurate calculation of mutual inductance is necessary to decide the working region of the coil. This paper presents an analytical calculation of mutual inductance between two planar spiral coils under angular misalignment conditions. By solving the Neumann integral formula, mutual inductance is derived for constant current-carrying coils, and the final mutual inductance value is calculated numerically. The influence …of angular misalignment of the coil, which can be due to nutation and spin angles, on mutual inductance is studied in detail. The mutual inductance of the spiral coil is calculated for different misalignment cases. The accuracy of the calculation results is verified by comparing it with conventional formulas (mainly the Liu, the Babic formula, and the Poletkin formula) and by simulation using the finite element method. The proposed method is a more generalized and simpler one that can be used to calculate the mutual inductance of any size of coils, either spiral or circular, with any lateral and angular misalignments. Finally, a couple of spiral coils are fabricated to validate it experimentally. The comparison of the simulation and experiment results with the calculation result shows its accuracy. Thus, the proposed method can be applied to compute mutual inductance in any angularly misaligned coupling coils for the optimization of the wireless power transfer and their design. Show more

Keywords: Neumann integral formula, mutual inductance, angular misalignment, wireless power transfer, spiral coil

DOI: 10.3233/JAE-230060

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 3, pp. 235-249, 2024

Authors: Wang, Yunhao | Liu, Zhiguang | Yang, Zhiyong

Article Type: Research Article

Abstract: It is significant to balances torque and vibration performance for the surface-mounted permanent magnet (PM) machines. This paper proposes a functional magnet structure to suppress the vibration response of integral-slot surface-mounted PM machines. At the same time, the torque ripple is also greatly reduced without sacrificing the average torque. Firstly, taking the 48-slot/8-pole PM machine as an example, the main sources of the air-gap radial force are analyzed based on the Maxwell stress equation. Thereby, the main PM flux density harmonic components that contribute to the radial force are pointed out. Secondly, the design method of different functional magnet structure …is investigated. Then, the effects of different magnet shapes on the torque and vibration performances are compared. The result shows that the proposed sinusoidal+3rd-order harmonic injection functional magnet structure can effectively improve the vibration performance without sacrificing the average torque. Finally, the prototype of the 48-slot/8-pole PM with functional magnet structure is manufactured, and the experiments are carried out for validation. Show more

Keywords: Integral-slot, radial force, surface-mounted magnet, torque, vibration reduction

DOI: 10.3233/JAE-220311

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 3, pp. 251-268, 2024

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

Article Type: Research Article

Abstract: The Electromagnetic Damping Generator (EDG) used for petroleum exploration is faced with the problem of high local temperature during its downhole work. To avoid the damage to its internal circuit caused by high temperature, the key EDG circuit is required to be heat-resistant based on the electromagnetic induction principle and the current heating effect. First of all, the working condition with the maximum heating power was figured out after studying the heating power characteristics of EDG. Then the multi-field coupling model of the temperature field, electromagnetic field and structure of the damper, as well as its iterative analytic model were …established to identify the relationship between the temperature rise of the key location of the damper part and its working time in the downhole environment and the room-temperature experimental environment, which provided data support for EDG optimization design. Finally, a EDG prototype was developed, and the test bench was set up by replacing the load with resistors to verify the accuracy of the iterative analytical model. The results showed that the temperature value calculated by the model well fit the experimental value. Therefore, the downhole operation reliability of the EDG and the safety of corresponding bench tests are guaranteed, which has certain guiding significance for EDG optimization design and its experimental study. Show more

Keywords: Electromagnetic Damping Generator (EDG), high temperature, multi-field coupling, iterative analytical model, bench test

DOI: 10.3233/JAE-220309

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 3, pp. 269-285, 2024