Coordinated Optimal Reactive Power Control of Renewable Energy Base Considering Grid-forming Energy Storage Station

This paper addresses the challenge of voltage stability in renewable energy bases lacking synchronous power supply support, which exhibit low immunity and weak support compared to traditional thermal power-dominated systems. The use of grid-forming energy storage stations (GFMS) is proposed as an effective solution. The control principle of GFMS is analyzed, and its power adjustment ranges under steady-state and dynamic conditions are determined, leading to the establishment of a GFMS operation model. A coordinated optimal reactive power control strategy is then introduced, incorporating GFMS auxiliary governance to meet reactive power coordinated optimization and real-time voltage support needs. In the reactive power coordinated optimization stage, day-ahead and intra-day centralized optimization of reactive power sources is performed, aiming to optimize economic efficiency and maximize dynamic reactive power reserve capacity. For real-time voltage support, a GFMS voltage control strategy is developed based on the voltage support requirements of the grid-connected point. A case study of a renewable energy base in northwest China without synchronous power support validates the strategy's effectiveness. Results demonstrate that the proposed coordinated optimal reactive power control strategy significantly improves the security and stability of the renewable energy base and fully leverages the capabilities of GFMS.