Frequency Regulation and Scheduling Framework for Hybrid Energy Systems in Isolated Grids

The increasing penetration of renewable energy sources and energy storage systems into power grids, particularly in isolated and hard-to-reach territories, necessitates advanced control strategies to ensure stability and reliability. This paper proposes a coordinated control system for hybrid energy system comprising wind turbines, an energy storage systems, and conventional synchronous generators connected to a grid. The control strategy aims to maximize wind turbine power utilization, minimize the number of active synchronous generators, and maintain grid stability by effectively managing power flows. Key features include using the storage system as a dynamic slack bus within defined charge limits, providing frequency support through coordinated actions, and implementing logic for optimal synchronous generators commitment. Simulation results demonstrate the effectiveness of the proposed controller, showing significantly improved frequency response during disturbances and reduced reliance on conventional generation compared to a system without the hybrid energy system integration. The developed control strategy enhances the operational flexibility and stability of power systems incorporating high shares of variable renewable energy sources.