Vertical-Axis Wind Turbines Using Permanent Magnet Attractive Type Passive Magnetic Bearings

This paper presents a novel design of a vertical axis wind turbine (VAWT) for power generation purposes. Using the effects of magnetic suspension, wind generator will be suspended on permanent magnets (PMs) as a replacement for ball bearings, which are normally used on conventional wind turbines. The features of this system are effective for saving energy, avoiding heat generation and preventing mechanical contact. Electrical power will then be generated with an axial flux generator, which incorporates the use of permanent magnets and a set of coils. The proposed VAWT model has the ability to achieve stability at different wind speeds in both the axial and radial direction. Moreover, the proposed model has a novel advantage consisting in adjustability of the axial and radial stiffness and ability to avoid critical speed reducing the vibration during the rotation of the wind turbine. The proposed model is characterized by simple structure and low-cost design. Finally, the effectiveness of the model is verified by the experimental results.