Methods and systems for alleviating the loads generated in wind turbines by wind asymmetries

A method for alleviating rotor asymmetric loads in a variable-speed wind turbine having pitch and torque control means comprising the following steps: providing a control law that determines the pitch to be applied individually to each wind turbine blade for counteracting rotor asymmetric loads (such as wind shear, upflow, yaw misalignment) using wind speed and wind direction measurements at the wind turbine, values of the wind features that cause rotor asymmetric loads and configuration parameters of the wind turbine (whether real-time values or statistical values at the wind turbine site), said pitch to be added to the collective pitch ¸ 0 ; implementing said control law in the wind turbine control means. The invention also refers to a wind turbine control system arranged for implementing said method.