If you haven't watched the above embedded Youtube video, you should. It shows the various parts of a wind turbine (both sub-megawatt & multi-megawatt types). If you are involved in anyway with the wind energy industry, you'll get a very clear picture of the actual composition of the major parts inside a wind turbine.
Of course, the construction of wind turbines do vary depending on the manufacturer and in future, wind turbines may look drastically different from this one, but the video/animation gives a general picture of what exists today. Please do share it with people who are not aware of the components of wind mills and think of wind turbines as simple electricity generation devices.
As you maybe aware, wind turbines have a long cylindrical tower that is broader at the base and narrows as you go up. There is a door through which maintenance engineers can enter the wind mill at the bottom and they can climb up to the nacelle using long ladders or a small elevator. The bottom part of wind turbines may also house a transformer in order to increase the electrical voltage to make it more suitable for long-distance transmission.
The nacelle is the long cubical 'neck' part of the wind turbine that is located just behind the blades. The nacelle consists of a shaft that is attached to the rotating wind turbine blades and will rotate, as the blades rotate. This shaft passes through a gear box, brake and then through a generator (all kept inside the nacelle), which produces electrical current. There are wind sensors attached at the top of the nacelle that can gauge the wind speed/ direction and the nacelle can rotate/position itself based on the wind direction.
The front part of the wind turbine consists of three blades that is attached to the shaft. Of course, flowing wind turns the blades and they rotate in unison. Each wind turbine blade can also individually adjust its position, according to wind conditions. There are components like encoders and PLC's/ power electronic components that can measure/control the direction and speed. Of course, there are cables that run from the generator to the bottom of the turbine and outside in order to transmit the generated power.
That gives you a very short description of the major components that can be found inside a wind turbine. The above embedded video gives you an audio-visual introduction with much more details that will enable you to understand the various parts of a wind turbine, better.
