A New Technique：Research and industrial application of a novel compound permanent magnet synchronous machine

• Published in: Journal of Zhejiang University. A. Science Vol. 10; no. 4; pp. 471 - 477
• Main Author: Cheng-zhi FAN Ming-xing HUANG Yun-yue YE
• Format: Journal Article
• Language: English
• Published: 2009
• Subjects: 工业应用; 工作曲线; 永磁同步电机; 直接驱动; 磁场分布; 脉动转矩
• ISSN: 1673-565X; 1862-1775

We propose a novel kind of compound permanent magnet synchronous machine （CPMSM）, which is applicable in low-speed and high-torque situations. We first explain the structure of the CPMSM. Based on theoretically deducing the calculation formulae of the CPMSM electromagnetic parameters, we analyze the operating characteristics of the CPMSM, and obtain the power-angle curves and working curves. The no-load magnetic field distribution and the cogging torque are analyzed by applying the finite element method of three-dimensional （3D） magnetic fields, to determine the no-load leakage coefficient and the waveform of the cogging torque. Furthermore, the optimal parameters of the permanent magnet for reducing the cogging torque are determined. An important application target of the CPMSM is in direct-drive pumping units. We have installed and tested a directdrive pumping unit in an existing oil well. Test results show that the power consUmption of the direct-drive pumping unit driven by CPMSM is 61.1% of that of the beam-pumping unit, and that the floor space and weight are only 50% of those of a beam-pumping unit. The noise output does not exceed 58 dB in a range of 1 m around the machine when the machine is 1.5 m from the ground.