Analysis of the passive yaw mechanism of small horizontal-axis wind turbines

This paper analyzes passive yaw mechanisms for small, fixed-pitch, variable-speed wind turbines. There are several mechanisms which can provide passive yaw-control. This paper compares different passive yaw-control mechanisms by considering both their technical viabilities and costs. It is demonstrated that small wind turbines with a tilting tail hinge and an offset pivot axis are simpler and more economical than other passive yaw-control small wind turbines. Finally, the paper summarizes the working principles of the passive-yaw mechanisms for both wind direction tracking and over-speed protection under high winds, and presents the mathematical calculation of the back-position-torque, aerodynamic moment which indicates the torque balance throughout the working wind speed range.