As the penetration of wind power in power system increases, the operation and scheduling of power system face more technical challenges. Traditional deterministic generation dispatch methods cannot ensure system operation security because they don't consider incorporate wind power uncertainties appropriately. Based on the wind power prediction interval, a robust dispatch scheme is introduced for intra-day active power scheduling, in which wind farms are controlled with the maximum-power-point-tracking strategy mostly. This scheme is featured with flexibility and practicality. In combination with this scheme, a robust interval economic scheduling model is formulated and further simplified as a quadratic programming, which takes into account the response of automatic generation control (AGC) generators adjustment. Finally, simulations are conducted on a test 10-units power system in 96- time intervals. The robustness and economy of the robust dispatch scheme is verified.