Robust control of hydro generators for wind power variability accommodation

Abstract

The increased penetration of wind power presents new control challenges to the power system such as frequency control. Hydro generators have long been the primary actors in power system frequency regulation, but their control framework is predicated upon the dynamic characteristics of traditional power systems. In this paper, a robust control method is proposed to integrate hydro generators to address increased frequency deviations introduced by wind power variability. First, the state-space model of the entire power system is derived for the control design of hydro units. In order to consider the impact of hydraulic system dynamics, a detailed model for hydroelectric power plant is developed. Also, characteristics of wind power fluctuations are considered by the form of weighting function. Then, the robust controllers are synthesised using an existing linear matrix inequality (LMI) algorithm. Finally, the WECC 9-bus test system is used to verify the performance of the designed hydro controllers for regulating frequency deviations.