Control Strategy for Improving the Safety and Stability Margin of New Energy Power Grids with Grid-Connected Converters

With the large-scale grid connection of renewable energy(RE), the problems of lack of inertia support and reduced stability margin in power systems are becoming increasingly prominent. This paper focuses on the core advantages of grid-forming converters (GFCs) and proposes a control strategy for GFCs to improve the safety and stability margin of RE power grids. First, a grid-connected model and control system of the GFM are constructed. Then, the transient characteristics after a fault under traditional control strategies are studied, including transient power angle characteristics and transient voltage characteristics. On this basis, a three-order transient power angle control strategy and transient current control strategy for the GFM are proposed, effectively improving the safety and stability margin of the power system. Finally, simulations verify the correctness of the proposed method.