How Do Wind Power Systems Work?
To understand how Wind Turbines works, we break the system into its basic components.
A rotor generally consists of three blades attached to the rotor hub that spins when in contact with strong wind. The blades are designed in a similar way to those on an aeroplane wing, breaking the wind-stream to create differing pressure regions. The blades move from the high-pressure to the low-pressure region, creating a movement called lift. With all three blades connected to a rotor hub, the linear lift is converted into a spin. The energy from the wind is now available for power generation.
2) Shaft and gears:
The shaft is connected to the rotor hub and spins along with it. A Windmill's shaft spins slowly with about 15-20 rotations per minute (rpm), insufficient to power a generator. To overcome this, the larger shafts are connected to smaller ones via gears, converting the higher energy into higher rotations. The smaller shafts run around 1000-1800 rpm, providing sufficient energy to run the electric generator.
3) Electric Generator:
Like any other generator, the role here is to convert the input rotational mechanical energy into electricity. The end of the smaller shaft is connected to magnets surrounded by coils of wires. When the shaft rotates, it spins the magnets inside the conducting coils, generating voltage. The voltage then pushes the current to the power-lines for storage or consumption.
A Nacelle houses the shafts, gears, controller and the electric generator. It sits on top of the tower.
The controller is connected to the Anemometer, which measures the wind speed. It is located at the end of the Nacelle, ensuring optimum operating conditions for the Wind Turbine. The controller starts the machine at wind speeds of 8 to 16 miles and stops the blades at speeds of over 55 miles - to protect from any damage.
6) Pitch and Yaw:
The Yaw motor connected to the Wind Wave ensures the rotor is facing upwind, guaranteeing maximum performance. Like the Anemometer, the Wind Wave is located at the back of the Nacelle. The pitch controller rotates the blades along its axis to control the angle of wind approach. More open or higher pitch perform better at low wind speeds and closed or lower pitch works better at high wind speed. Pitch angles also protect the blades against stress during fast winds.