International Journal of Applied Electromagnetics and Mechanics - Volume 59, issue 2

Authors: Lin, Hao | Geng, Haipeng | Du, Tingchen | Xu, Xiangming | Zhang, Yanyan | Cheng, Wenjie | Yu, Lie

Article Type: Research Article

Abstract: The electromagnetism and rotor dynamics have been drawing great research interest due to their significance in the design of the high speed permanent magnet synchronous motor. However, it is challenging but essential to study the rotor supported by air foil bearings with cylindrical permanent magnet. Here the approach is reported to analyze a high speed PMSM rotor at the rating of 28.5 kW and 96,000 rpm. Through the analytic method and the finite element simulation, the expression for the magnetic flux density is obtained. Based on the rotor-bearing system discrete model, the critical speed is calculated by Campbell diagram. It comes to …the conclusion that the radius and length of cylindrical permanent magnet is reciprocally related to the magnetic flux density and critical speed values. Finally, results of the PMSM experimental device operating at 96,000 rpm are represented by rotor frequency spectrum and orbit diagram. Show more

Keywords: High speed motor, cylindrical permanent magnet, magnetic field, rotor critical speed, air foil bearing

DOI: 10.3233/JAE-171157

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 2, pp. 755-764, 2019

Authors: Sirewal, Ghulam Jawad | Lipo, Thomas Anthony | Kwon, Byung-il

Article Type: Research Article

Abstract: This paper presents a research on reducing the torque ripple in a brushless wound rotor synchronous machine (BL-WRSM). The basic brushless topology generates a third-harmonic current component in the stator to excite the rotor. The rotor has two types of windings, field winding and harmonic winding, which are connected with each other through a rotor mounted diode rectifier. Field winding has same number of poles as that of the stator armature winding to generate torque while the harmonic winding has three times the number of poles as that of the armature winding, to induce third harmonic current component and excite …the field winding. In this paper, the rotor harmonic winding is split in two branches and further a capacitor is connected in series with one branch to create a phase difference. Phase difference between the two harmonic winding branches reduces the peak-to-peak value of the DC current fed to the field winding and hence the torque ripple is reduced. Finite Element Analysis (FEA) is performed to verify the reduction in ripple percentage. Show more

Keywords: Wound rotor, synchronous machine, brushless excitation, torque ripple, ripple reduction, two-phase

DOI: 10.3233/JAE-171134

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 2, pp. 765-773, 2019

Authors: Sheng, Feng | Geng, Haipeng | Zhang, Bo | Yang, Baisong | Xia, Kai | Yu, Lie | Cheng, Wenjie

Article Type: Research Article

Abstract: This paper describes a program development in testing a 100 kW Permanent Magnet Synchronous Motor (PMSM) using multi-leaf foil bearings with bump foils. The testing program includes the motor speed up to 43000 rpm, and then slow down to zero speed. The orbit of the rotor and the electrical parameters of the motor are obtained. The success in the experiments shows that the design and fabrication of the compliant gas foil bearings and motor can provide a useful guide to the development of an advanced high speed rotating machinery.

Keywords: High-speed, permanent-magnet synchronous motor, multi-leaf foil bearings

DOI: 10.3233/JAE-171069

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 59, no. 2, pp. 775-783, 2019