说明：  Load frequency control (LFC) plays an important role in maintaining constant frequency in order to ensure the reliability of power systems.With the large-scale development of sustainable but intermittent sources such as wind and solar, such intermittency challenges the LFC problem. Moreover, the generation rate constraint (GRC) of power systems also complexes the LFC problem. Concerning the constraint, this paper addresses an integral sliding mode control (I-SMC) method for power systems with wind turbines.