Wind gust 10 to 15 knots, the term "gusts" is used while "strong gusts" is used for departure of 15 to 25 knots, and "violent gusts" when it exceeds 25 knots. Wind gust A gust or wind gust is a brief increase in the speed of the wind, usually less than 20 seconds. It is of a more transient character than a squall, which last minutes, and is followed by a lull or slackening in the wind speed. Generally, winds are least gusty over large water surfaces and most gusty over rough land and near high buildings. The wind is measured using
Variable speed wind turbine length of the blade, formula_4 is the velocity of the wind, and formula_5 is the power coefficient for the wind turbine. The power coefficient is a representation of how much of the available power in the wind is captured by the wind turbine. The torque, formula_15, on the blades is given by the ratio of the power extracted to the rotor speed, formula_2: formula_17 The rotor speed can be related to the wind speed, formula_4, through the tip-speed ratio, formula_6: formula_1 Thus we can get the following expressions for torque and power: formula_21 and formula_22 From the above equation, we