Simulation-based Online Operating Policy for Wind-storage Plants

The integration of battery energy storage systems is popularized in wind farms to mitigate generation volatility. For a integrated wind-storage plant, selling energy to a power market is a typical application scenario at the generation side. The revenue maximization problem is challenging as the operation policy has to be settled under generation and price uncertainty. This paper presents a novel online operation policy for wind-storage systems through a simulation-based optimization method. The Lyapunov optimization model is introduced first to construct a base policy that can be expressed explicitly. Then, in the online stage, the state-action value is estimated by sampling the action values and conducting scenario-based simulations for future operation periods based on the Lyapunov policy. The computational complexity of the simulation is alleviated by sampling the output power instead of the multi-dimensional control variables. Finally, the economic efficiency is validated with numerical tests over a yearly horizon.