Although wind energy is a clean and renewable source of electric power, many challenges must be addressed. Wind turbines are complex machines, with large flexible structures working under turbulent and unpredictable environmental conditions, and are connected to a constantly varying electrical grid with changing voltages, frequency, power flow, and the like. Wind turbines have to adapt to those variations, so their efficiency and reliability depend heavily on the control strategy applied. As wind energy penetration in the grid increases, additional challenges are being revealed: response to grid disturbances, active power control and frequency regulation, reactive power control and voltage regulation, restoration of grid services after power outages, and wind prediction, for example.