Under normal operational conditions, yaw movement may occur when the rotor is stopped or when it is turning. When the rotor is stopped, the force applied by the yaw drive needs to overcome only the inertia of the nacelle and the frictional forces at the yaw bearings to cause the nacelle to yaw. Additional force…
Once the yaw ring is installed, the nacelle main frame must be turned over in order to complete the yaw system assembly. Temporary legs are installed, and fixtures are added to the yaw ring. The main frame is lifted, and one side is let down while the frame is rotated. Here you can see the…
The yaw ring assembly fits in a machined groove in the nacelle main frame casting. Several studs are inserted to locate the ring as it is lowered into the groove. The ring is lifted and carefully lowered into position. The remaining studs are inserted and run down. Spacers are added, then nuts are installed and…
Let’s take closer look at a typical sensor for a large wind turbine. The sensor mounts to the main frame; its gear is driven by the yaw ring. This sensor employs an incremental encoder that tracks nacelle position, along with a group of limit switches dedicated to cable twist control Here we can see the…
Let’s take a closer look at some of the sensors used in the yaw control system. Potentiometers,encoders and ultrasonic sensors may be used to detect wind direction. A potentiometer is a variable resistor consisting of a resistive strip, 3 terminals, and a movable wiper. The movable wind vane is connected to the wiper. As the…
A wind turbine is a sophisticated system of components that must all work together to efficientlyproduce power. Like most sophisticated systems, it can be divided into sections. Some sections are dedicated to capturing the wind energy. Other sections convert the mechanical kinetic energy into electrical energy. All of the sections depend on a control system…
Power from the yaw motors is transmitted to the yaw ring through a reduction gearbox which provides both speed reduction and torque multiplication. This yaw drive uses a planetary gearbox with the motor mounted vertically at the top. Planetary gearboxes are often used on commercial wind turbines because they offer high reduction ratios from a…
The main parts of the yaw brake hydraulic system and their functions are Accumulator: The accumulator stores fluid under pressure, and serves as a backup source of clamping pressure if system pressure is lost. Bleed Valve: Used to drain fluid from the accumulator to relieve pressure during service operations. Brake Calipers: Pressure in the brake…
The primary mechanical parts of the Yaw System are This section provides information about the relationship of the yaw bearing, yaw ring, and brakes. Yaw rings The yaw ring is a large gear that engages the pinion gears of the yaw motor gearboxes. Because these gears carry high loads, proper lubrication is important to prevent…
The wind turbine yaw control system provides two functions that are crucial to safe and efficient operation: The nacelle must point directly into the wind for maximum efficiency. Also, a rotor disk that is not perpendicular to the relative wind experiences higher loading on the portion of the disk that is closest to the wind….