Wind turbines are rotating machines that convert the wind’s kinetic energy into mechanical energy which in turn is converted into electricity.
Turbines used in wind farms for the commercial production of electric power have three blades, and motors controlled by servo drives point them in the direction of the wind. The blades have high tip speeds – up to six times the wind speed – and are highly efficient, with low torque ripple that contributes to good overall reliability. The blades range in length from 20 m to 40 m or more, and they can be controlled by Elmo’s high performance digital servo controller – the Tiger 50/600. Elmo’s Eagle 35/200 – a compact, high power and intelligent servo drive – is used as a backup drive to handle system operations in the event of an emergency or malfunction.
The blades rotate at 10 – 22 rpm, though the more advanced models operate at a constant speed. In this application solution, the servo drives control the motor blades which continuously change their angle with respect to the flow of the wind in order to maintain a constant rotational speed. All turbines are equipped with safety shut-down features to avoid damage at high wind speeds.