Proposed in this paper is a wind power prediction model considering both the smoothing effect and thewake effect,which helps to obtain the speed of wind turbines in different spatial positions by simulating the influ-ence of the wake effect on the wind speed and by considering the delay of wind transmission.The model also helpsto characterize the smoothing effect of power output by overlapping the power to shape power output curves.The re-sults of simulation and case study show that the proposed model is applicable for evaluating the impact of wind pow-er farms' input power on the system with high efficiency and precision,and that it accords well with practical windpower farms,so that it is useful for the correction of power units' reserved capacity and ramping rate as well as forthe appropriate assessment of power system reliability in the presence of wind power farms.