The yaw system of the wind turbine is also known as a means of wind, and its role in that when the wind velocity vector direction changes, it is possible to quickly and smoothly aligned with the wind, so that the maximum wind wind wheel. Common Rudder small micro-wind turbine wind, it is mainly composed of two parts, one tail, mounted on the tail boom and rotor shaft parallel or angled. In order to avoid the influence of the wake flow, also may be upturned tail, mounted in a higher position. Small and medium-sized fan wheel available as wind device, it works as follows: when the wind direction changes in the wind behind the wheel steering wheel (the plane of rotation of the wind wheel rotation, rotation perpendicular to the plane) and wind through a set of gear drive system round deflection, realign the wind direction when the wind wheel, the wheel stops rotating, the end of the wind process. Large and medium-sized wind turbines generally use electric yaw system to adjust the wind wheel and so it is on wind direction. Yaw systems typically include the induction wind direction vane, yaw motors, yaw planetary gear reducer, rotator gear. Its working principle is as follows: vane as the sensing element will pass wind shift electrical signal to the the yaw motor control loop processor, processor after comparison clockwise or counterclockwise yaw command issued to the yaw motor, in order to reduce the the gyroscopic moment when the yaw motor speed reducer through the coaxial connection deceleration, the yaw moment is applied in the rotator gear, driven by the wind wheel yaw wind, lost power after the completion of the wind vane signal, the motor stops working, the yaw process ends.