Wind Turbine System Components

Wind turbines convert the natural kinetic energy of the wind into electricity. They generate electricity as long as the wind is blowing.

The main parts of a small wind turbine system include the nacelle, blades, and rotor. It also includes a charge controller, battery and cables. There are also grid-tie systems that don’t use batteries but send power directly into the electric grid.

Blades

Depending on their design, wind turbine blades can be quite long. They must support the weight of the rotor and withstand significant axial, compressive and bending loads. They must also resist fatigue caused by repeated cycles of alternating load-direction reversals, in combination with variable loading and cyclic torsional stresses.

As a result, blades are typically made of carbon fiber composite materials. These are produced by vacuum assisted resin transfer molding (VARTM) or by a similar process. A wide range of structural tests is performed on full-scale prototypes to verify that the composite structure meets the required performance.

The blades must also be able to extract energy at the optimal wind speed, which depends on their size and power coefficient. This requires a control loop for the generator torque and the blade pitch actuator model to optimize power capture. The loop is split into three regions: the partial-load region, the rated operation point and the full-load region.

Rotor

The rotor is the part of the wind turbine that interacts with the wind to produce electricity. It consists of a set of blades that are attached to the hub by a shaft and that rotate between 8 and 20 times per minute.

The blades are designed to generate a high amount of mechanical energy (torque) from the wind by using aerodynamic principles. The number of blades is determined by balancing performance with cost and system reliability.

The rotor blades are loaded cyclically by wind and wind turbine system shear (changes in wind speed at different heights). The load variations cause the blades to bend flatwise and edgewise, resulting in stress fatigue. To reduce the loads, some new blade designs have the ability to alter their pitch angle (turning them into and away from the wind). The ability to control the speed of rotation continuously enables the use of higher tower heights and reduces energy loss due to wind speed changes.

Axis

Wind energy systems capture the wind’s energy to produce electricity. They convert mechanical rotation into electrical power and have other systems to control, start, stop, and operate the turbine.

The rotor shaft in most wind turbines is oriented horizontally to take advantage of the prevailing winds. This configuration allows the electric generator and other components to be placed near the ground, which improves accessibility for maintenance.

A taller tower can also double a wind energy system’s output by raising the turbine above air turbulence created near the ground by landforms (or orography). The tower also raises the rotor blades away from obstructions and other factors that reduce performance. It requires a foundation that is strong enough to support the weight of the equipment and to resist wind forces. Typically this is made of reinforced concrete. The foundation must also allow the turbine to be raised and lowered for maintenance.

Gearbox

The gearbox transforms the slow rotation of a wind turbine’s blades into a faster rotating speed to power a generator. It is often referred to as the heart of the system and is one of the most critical components in a wind turbine.

A gearbox increases the rpm (revolutions per minute) of the ev charging pile low-speed shaft by connecting it to a high-speed shaft that runs at a much higher rpm. This is accomplished by using a series of gears, called planets, that revolve around a single center gear called the sun gear.

While the rpm of the high-speed shaft can be adjusted, the low-speed shaft is fixed to match the rotational speed of the blades. As a result, the gearbox is subjected to cyclical loads that can cause failures. Fortunately, operational experience reveals that gearbox reliability is steadily improving.

Generator

The electrical generator converts the mechanical energy from rotor blade rotation into electricity. It’s also called an alternator or a dynamo. It can produce low voltage DC current to charge batteries or higher AC sinusoidal power for connection directly to the grid.

It may be powered by a simple direct drive or use a gear box to speed up the initial rotational speed. Then, it’s connected to the rotor via a main shaft. Some turbines are designed to run “upwind,” facing into the wind; others are designed to run “downwind.”

The rotor shaft is connected to a low-speed shaft that enters a gearbox. The gear box increases the rotational speed and feeds it into the generator. The generator turns the initial rotation into electricity by interacting with magnetic fields in a copper coil known as an armature. Power is produced proportional to the wind speed cubed until the generator reaches its cut-in wind speed.

Tower

The tower of a wind turbine is a critical component. It supports the nacelle and its blades, as well as the generator and other electrical systems. Its construction requires coordination and precision.

Loads on a tower are caused by gravity loads, aerodynamic forces transferred from the rotor, and wind-induced pressure. Wind velocities vary by altitude, with the fastest speeds near surface level and the slowest at higher altitudes.

To maximize energy production, the rotor rotates at a speed that matches the wind’s velocity. A pitch system uses gears to control this rotational speed. The system also controls the rotor’s direction by communicating with the wind vane and anemometer.