The opposing wind forces are completely neglected with the help of a deflector such that the speed of the turbine shaft is increased faster than normal, even at very low wind speed (1m/s). Almost all the wind turbines extract only 50 to 60% of total wind power due to low speed. This is due to the wind resistance in the blades. Wind turbines are generally located at a higher altitude nearly 100 feet above the ground level in order to acquire a large wind power. The main objective of our project is to increase the speed of the rotor shaft even at low speed of wind (1 m/s), using a modified design in order to increase the power production. The main objective of our project is to increase the speed of the rotor even at low speed of wind in vertical axis wind turbine. Every year, wind produces only a small amount of the electricity to country, but the usage of electricity is growing every year. One reason wind farms don’t produce more Electricity is that they can only run when the wind is blowing at certain speeds. In Tamil Nadu power cut is most common nowadays, many villages experience about 16 hours power cut. In Coimbatore about 40000 small scale industries losing 15000 cores a month due to frequent power cut.Almost all the wind turbines extract only 50 to 60% of total wind power. This is due to the wind resistance in the blades. In order to find where the 40% power loss occurs, we researched and found the reason after a few prototypes. The reason is explained below:
Consider a wind flowing in a particular direction such that the vertical axis wind turbine starts rotates the shaft in clockwise. There is an opposing wind forces acted on the other side of the blades which slows down the speed of the rotation of the shaft.Hence we placed a deflector such that there is no opposing wind forces to hinder the rotation of the shaft. With some additional design feature the wind flow is directly concentrated on the turbine blades to increase the speed of rotation. The opposing wind force that hinders the rotation of the the shaft is neglected with the help of the deflector which alters the path of the wind flow. Some of the modification which is done to increase the velocity of the wind is as follows:
Nozzle is a device which converts low velocity fluid at inlet into high velocity fluid at exit.
Deflector: It neglects the opposing wind forces and deflects the wind.
Guide: It guides the wind to flow in a circular path and to rotate the blade.
When the speed of the wind turbine increases tremendously it results in damage to the rotor at a particular point. Hence a braking system has to be adopted in the system to stop the rotor at this situation. This is said to be cut-out speed normally the cut in speed ranges from (25 m/s).