This paper presents a robust control design to integrate hydro generators to address increased frequency deviations in power systems with high wind power penetration. A robust control design framework for hydro governors is proposed in order to particularly tackle with disturbances from wind power fluctuation. First, by combining state equations of hydro, thermal, and wind generators through the power flow equations of network, a state space model of the entire power system is derived for the control design of hydro generators. In particular, the characteristics of wind power variations and the hydraulic system dynamics of hydroelectric power plants are implemented in the system model. Then, the H-infinity-based robust controller is synthesized by reducing the order of the system model and using the linear matrix inequality method. Finally, the IEEE 39-bus test system is used to verify the performance of the designed robust controller with 10-40% wind penetration levels. Simulation results are compared with a traditional PID controller. Research findings indicate that the proposed robust controller significantly reduces system frequency deviations and enables hydro generators to be more responsive to wind power variation in primary frequency regulation of power systems.