Coordinated Power Smoothing Control for Wind Storage Integrated System with Physics-informed Deep Reinforcement Learning

However, the intermittent nature of wind power introduces inherent variability and uncertainty when integrated into power systems. As the wind power penetration level increases, the secure and reliable operation of power systems becomes a significant challenge [1]. In practice, the grid usually requires the active power fluctuation from wind farms to be confined to a specific value within a one-minute time window [2]. Therefore, Wind Power smoothing control (PSC) has emerged as a potential solution. Previous research has established two major categories of Power Smoothing Control for wind farms, including regulation control of wind turbines and indirect power control by Battery Energy Storage System (BESS). The former approach typically involves pitch angle control [3], rotor inertia control [4], and Direct Current (DC)-link voltage control [5], which require a different operation from maximum power point tracking, causing inefficiency and potential damages [6]. On the contrary, with a stronger capability of power smoothing, the BESS-based PSC coordinates the active power from BESS and wind turbine [7], providing rapid response to power fluctuation with high operability and little power loss. Recognizing the benefits of such Wind Storage Integrated Systems (WSIS) [8], incentive policies have been introduced to mandate the installation of BESSs from 10% to 30% of wind farms' installed capacity. WSIS facilitates wind power storage, allocating, and smoothing, enhancing delivery stability and energy management flexibility for both the grid and wind farm.