Question

Describe with a neat diagram, construction and advantages of a double bladed wind turbine

Answer 1

Wind turbines or wind system are accepted terms for devices that extract power from the wind and produce mechanical or electrical power.the term wind turbine is often reserved for machines that use rotors as wind energy collectors.

Wind turbine are classified as horizontal axis or vertical Axis turbines nearly all wind turbines manufactured today are horizontal Axis. Vertical Axis machine have been plagued with blade fatigue problems. In addition the routers on vertical are typically lower than those of horizontal axis. The latterpositioning pasand a disadvantage because the velocity of the wind decreases near the ground.

the most successful large depend configuration or three blade apartment designs build primary by European manufacturers. These turbines use a wind direction sensor and to yaw motor to rotate the rotor into the wind.this European turbines tend to rotate at slower velocities and are much more massive than US machines.

Two bladed turbines:

​​​​​​U.S designers tend to pursue lighter downwind to two bladed machines in an attempt to use material more efficiently. Using two blades rather than 3 offers significant material and weight saving.

another advantage of two bladed turbines is that the teetering motion greatly reduced uneven loads on the blade due to tower shadow.tower shadow is the increase in air turbulence as the wind flows around the tower.additional weight and cost saving can be made on a two bladed downwind rotary by making it a free yaw machine. The latter eliminate the weight and cost of yaw drive mechanism.

A major disadvantage of two bladed machine is that they are noiser.the machine must be run faster than 3 blade machines to produce the same amount of energy and the faster roter speed increase blade noise.

Construction:

Tower tower is a very crucial part of two bladed wind turbines that support all the other parts.it's not only support the turbines but rises the turbines to sufficient height so that it blade tips would be at safe height during rotation.the height of tower ultimately depends on the power capacity of wind turbines. This tower usually ranges from 40 to 100 meters.

blades are the main mechanical part of wind turbine. The blades convert wind energy into usable mechanical energy. When the wind strikes on The blade The blade rotates. This rotations transfer its mechanical energy to the shaft. The wind turbine blades can be 40 to 90 meter long.

the shaft directly connected to the hub is a low speed shaft. When the blade rotates the shaft spinsw the same RPM has the rotating. We couple the shaft directly to the electrical generator in case of a low speed generator. But in most cases the low speed main shaft is geared with high speed shaft gearbox.in this way the rotor blades transfer is mechanical energy to the shaft which ultimately and is into an electrical generator.

The wind turbine does not rotate at high speed rather it rotates gently at low speed but most of the electrical generator at high speed of rotation to generate electricity at a decide voltage level. so there must be some speed multiplication arrangement to achieve the high speed of the generator shaft.gearbox of the wind turbine does this. gearbox increase the speed too much higher value.

Generator is an electrical device that converts mechanical energy received from the shaft into electrical energy. Normally we use induction generator in modern wind turbines.

Power converter is an electrical device that stabilize the alternative output voltage transfer to the grid.