@Article{EE.2021.014143, AUTHOR = {Jungang Wang, Liqun Qian, Shuairui Xu, Ruina Mo}, TITLE = {Analysis of Electromagnetic Performance of Modulated Coaxial Magnetic Gears Used in Semi-Direct Drive Wind Turbines}, JOURNAL = {Energy Engineering}, VOLUME = {118}, YEAR = {2021}, NUMBER = {2}, PAGES = {251--264}, URL = {http://www.techscience.com/energy/v118n2/40961}, ISSN = {1546-0118}, ABSTRACT = {Wind turbine is a key device to realize the utilization of wind energy, and it has been highly valued by all countries. But the mechanical gear transmission of the existing wind power device has the disadvantages of high vibration and noise, high failure rate, and short service time. Magnetic field modulation electromagnetic gear transmission is a new non-contact transmission method. However, the conventional modulation magnetic gear has low torque density and torque defects with large fluctuations. In order to overcome the gear transmission problems of the existing semi-direct drive wind power generation machinery and improve the electromagnetic performance of the traditional magnetic gear transmission, this paper proposes a new transmission scheme of a non-contact semi-direct drive wind generator with a surface mount Halbach array modulated magnetic gear method, and considers the electromagnetic properties of the semi-direct drive modulation magnetic gear of the wind turbine. The finite element software is used to construct the model of the surface-mounted Halbach array magnetic gear and the conventional gear, analyzed the distribution of magnetic field lines of the two magnetic gears, calculated the air gap magnetic flux density of the inner and outer air gap, and obtained the main harmonics of the inner and outer air gap magnetic density; calculated the static torque and steady-state operating torque of the inner and outer rotors in the model, compared the air gap flux density, harmonics and torque of the magnetic gears. The simulation results show that the magnetic field modulation type magnetic gear of the surface mount Halbach array magnetic gear method improves the magnetic induction waveform of the inner and outer air gap, reduces the pulse torque fluctuation, and has a 60% higher static torque. Applying it to semi-direct drive wind power generation equipment not only overcomes the shortcomings of mechanical gears, but also has higher electromagnetic performance. Therefore, the surface-mounted Halbach array modulated magnetic gear can be used to replace the mechanical gearbox in the semi-direct drive wind power generation equipment.}, DOI = {10.32604/EE.2021.014143} }