International Journal of Applied Electromagnetics and Mechanics - Volume 70, issue 3

Authors: Zhou, Yongqin | Huang, Jianxin | Zhou, Lei | Tian, Hongbo

Article Type: Research Article

Abstract: To solve the complex calculation in the reliability evaluation of the motor system with the Markov model, this study developed a reliability evaluation method based on the hidden Markov model (HMM). Next, the developed method was employed in a type of permanent magnet hybrid segmented flux-switching machine (PMFSM). By analyzing and simplifying the components of the PMFSM system, the reliability measurement standard and the failure modes of the respective component were examined, and the relationships between the failure modes of each component and the system parameters were built. The optimal parameter observation sequence was determined by calculating the Minkowski distance, …and the HMM was iteratively calculated by using the Baum–Welch algorithm. Moreover, the state transition probability matrix of the system was built, and the system reliability was evaluated. As revealed from the calculation results, the reliability of the PMFSM system is significantly higher than that of the conventional structure at the same time, and the mean time to failure (MTTF) of the PMFSM system is 14.8% higher than that of the conventional structure. Compared with the conventional evaluation method based on the Markov model, the two methods have similar reliability results for conventional and novel PMFSM systems, and the variation trend is the same. It shows that the proposed reliability evaluation method is feasible and effective, and the calculation is simple. The work in this study provides a basis for the design of the novel PMFSM system, and a practical engineering method to efficiently evaluate the reliability of other motor systems. Show more

Keywords: Permanent magnet flux-switching machine (PMFSM), reliability evaluation, hidden Markov model, Baum–Welch algorithm

DOI: 10.3233/JAE-210119

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 229-251, 2022

Authors: Kang, Mei | Zhu, Shengdao | Sun, Yuhua | Zhou, Yunhan | Ji, Jinghua

Article Type: Research Article

Abstract: This paper presents a triple three-phase permanent magnet synchronous motor (PMSM) with shaped magnets for low vibration applications. Firstly, the features of the designed PMSM are investigated from three aspects, including triple three-phase windings, shaped magnets, and multi-layered housing. Then, the armature reaction, magnetomotive force, torque performance, and fault tolerance ability of the designed PMSM are investigated. Subsequently, the radial force of the designed PMSM with shaped magnets is studied, in which the radial force modulation effect is considered. In addition, the radial force and vibration reduction principle is elaborated in detail. The modal simulation and experiment are carried out, …and the vibration reduction effect of the designed PMSM is verified by the multiphysics vibration predicted model. The result shows that the vibration can be effectively reduced by the shaped magnets and multi-layered housing design, and the output torque of the designed PMSM has been reduced insignificantly thanks to the triple three-phase windings. Show more

Keywords: Permanent magnet synchronous motor (PMSM), triple three-phase, shaped magnets design, radial force, vibration reduction

DOI: 10.3233/JAE-210221

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 253-271, 2022

Authors: Wang, Chenxin | Liu, Ruiwan | Wang, Bin | Abu-Siada, Ahmed | Qiu, Li

Article Type: Research Article

Abstract: In the tube electromagnetic bulging, physical parameters of the driving coil are very important to the results of the electromagnetic forming, the height and outer diameter of the driving coil are the main geometric parameters that affect the distribution of the electromagnetic force and the axial tube uniformity. As such, this paper explores the influence of these two parameters on the workpiece relative uniform deformation under electromagnetic forming process from the aspects of magnetic force line characteristics, radial electromagnetic force distribution, and axial relative length. Results show that the changes of the height and outer diameter of the forming coil …can modify the characteristics of the magnetic force lines and the electromagnetic force distribution at the end of the tube. Compared with the short and coarse driving coils, the proportion of uniform deformation on the bulging axis of the tube with slender coil is increased by nearly 42%. Obviously, electromagnetic bulging based on driving coil can reduce the uneven distribution of electromagnetic force caused by the end effect of driving coil and lead to uneven axial deformation to a certain extent. Results reveal that the tube electromagnetic bulging based on slender driving coil is easy to achieve axial uniform deformation, this study provides a valuable reference for the uniform of the workpiece in tube electromagnetic forming. Show more

Keywords: Driving coil, electromagnetic forming, electromagnetic force, uniform deformation

DOI: 10.3233/JAE-220014

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 273-287, 2022

Authors: Sun, Dong | Di, Chong | Bao, Xiaohua | Li, Shihao | Zhu, Qinglong

Article Type: Research Article

Abstract: Skewed slots are widely used in many industrial applications because they can effectively reduce electromagnetic vibration and noise. In order to eliminate axial electromagnetic force in ordinary skewed slots rotor, a double skewed slot was proposed, which can useful reduce axial electromagnetic force and is superior to traditional skewed slots on reducing the electromagnetic vibration and noise. However, it still suffers from the problem of the difficult manufacturing process in large-sized submersible motors. In this paper, a radial skewed slot to reduce the electromagnetic vibration and noise is proposed, which has the advantages of a simple manufacturing process and obvious …effect about reducing noise. Large-sized submersible motors are noisier than ordinary motors but lack effective means to reduce electromagnetic vibration and noise. So this paper adopts 2-D FFT and multi-physics coupling analysis method to analyze and compare the performances of the straight slot and the radial skewed slot in large-sized submersible motors. Show more

Keywords: Electromagnetic force, noise, radial skewed slot, vibration

DOI: 10.3233/JAE-220016

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 289-302, 2022

Authors: Feng, Wei | Zhang, Kun | Liu, Zongyao | Liu, Baoguo | Zhang, Huijuan | Mei, Junwei | Wu, Luji

Article Type: Research Article

Abstract: The unbalanced magnetic pull (UMP) is one of the main vibration sources of the motorized spindle. A calculation model of UMP in a synchronous motorized spindle considering the magneto-thermal coupling is proposed in this paper. The finite element analysis models of the electromagnetic field and the temperature field of a motorized spindle are first established. Then a two-way coupling analysis method considering the effect of temperature variations on electromagnetic material properties of the motor is proposed. An experiment is conducted to verify the efficiency of this method. The thermal deformations of the spindle are calculated and used to analyze the …air-gap variations between rotor and stator of the built-in motor. The 3D finite element electromagnetic model is adopted to calculate the UMP in the motorized spindle. The analysis results show that the eccentricity caused by thermal deformation can generate large UMP in the motorized spindle. Show more

Keywords: Unbalanced magnetic pull, synchronous motorized spindle, magneto-thermal coupling, air gap length, thermal deformation

DOI: 10.3233/JAE-220034

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 303-321, 2022

Authors: Ye, Lezhi | Chen, Zhao | Ma, Zhongwei | Qiu, Haolin | Chai, Shiwei

Article Type: Research Article

Abstract: Aiming at slippage and belt breakage of large mechanical conveyor belts, a new type of water-cooled permanent magnet brake (WPMB) is proposed. In order to determine the braking performance of WPMB, a multi-physics coupling model and analysis method of magneto-thermal-structure are built. The braking torque and temperature characteristics of WPMB under different working conditions are obtained. Based on the magnetic vector potential equation, an electromagnetic eddy current model is established, and the variation trend of braking torque with speed is predicted. The temperature field model is built based on the equivalent thermal network method. Using multi-field coupling analysis method and …3-D FEM, the influence factors of WPMB braking torque are analyzed. Two test prototypes with rated speed of 78 rpm, braking torque of 3000  N⋅m are designed and developed. Braking torque characteristic tests and magnetic shielding characteristic tests at different speeds and continuous braking characteristic test are carried out. Experiments show that the proposed method provides very practical results to ensure the continuous and stable operation of WPMB. Show more

Keywords: Braking torque, eddy current, multi-physics coupling, permanent magnet

DOI: 10.3233/JAE-220070

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 70, no. 3, pp. 323-344, 2022