Empowering Grid Stability: Grid-Based Energy Storage in New Power Systems

This document explores the critical role of grid-based energy storage in enhancing stability within modern power systems, particularly as China's new energy installed capacity surpasses thermal power for the first time. It highlights challenges from high renewable penetration, such as low inertia, weak damping, and transient overvoltage, which traditional energy storage cannot address. The paper contrasts grid-following and grid-forming (GFM) converters, emphasizing GFM's ability to emulate synchronous machine behavior through rotor motion equations and reactive power droop control, providing independent voltage and frequency support. It reviews national and provincial policies mandating grid-type energy storage for new energy projects, including the 2025 Action Plan for New Energy Storage Manufacturing. Practical applications across diverse scenarios demonstrate GFM's effectiveness in weak grid conditions, mitigating broadband oscillation and ensuring fault ride-through. The document concludes that grid-based energy storage is essential for future high-renewable grids, offering a technical path to maintain stability and support China's carbon neutrality goals by 2060.