Coordination of Modified VIC and PSS for Frequency Restoration With Dynamic Damping Enhancement in Hybrid Power Systems
Abstract
Virtual Inertia Control (VIC) is important to emulate synthetic inertia and damping in Renewable Energy Source (RES) systems. However, its ability to restore steady-state frequency and provide dynamic damping remains limited. Moreover, VIC implementation as a fast-response controller in hybrid power systems must be coordinated with the Power System Stabilizer (PSS) in the Synchronous Generator (SG) to mitigate undesirable dynamic interactions. This paper proposes a VIC modification by integrating the Integral Frequency Restoration and Dynamic Damping Compensator mechanisms (VIC-IFR-DDC). The IFR eliminates residual steady-state error during frequency restoration, and DDC enhances the synthetic damping characteristics. The VIC-IFR-DDC is implemented at the aggregated photovoltaics, wind turbines, and battery energy storage systems, and coordinated with the PSS to achieve complementary stability enhancement on both the RES and SG sides. A multi-objective coordination framework is formulated using the Starfish Optimization Algorithm with Benson Scalarization (SFOA-BS). The controllers are tested on standardized one-area and three-area interconnected power system models. The coordinated controllers by SFOA-BS have improved the damping ratios by 15.29% and 11.51% in one-area and three-area power systems, respectively. Based on time-domain simulations, the coordinated controllers enhance the frequency nadir by 27.99%, the rate of change of frequency by 17.63%, the steady-state restoration time by 40.02%, and the deviation error by 5.42%, on average. In multi-area disturbances, it also enhances the frequency and power transfer responses by 17.62% and 4.99%, on average. Overall, the results demonstrate the robustness and scalability of the coordinated VIC-IFR-DDC and PSS across transient, dynamic, and steady-state responses in time-domain simulations to support sustainable power and energy systems.