By integrating power flow model including wind power generators with conventional static security Available Transfer Capability（ATC） model, a new semi-smooth ATC model is constructed, which considers wind power generators connected to power system and static security of power system simultaneously. Then, based on the smoothing strategy and method, the smooth ATC model including wind power generators is constructed and the smoothing Newton method is adopted to solve the ATC model. Numerical simulation results of the IEEE 30-bus and 118-bus system show the proposed model and algorithm are feasible and effective. Finally, the impact of wind power generators connected to power system on ATC is analysed and compared with simulation results of ATC model without wind power generators.