Abstract: With the integration of a high proportion of renewable energy into the grid, the volatility and uncertainty of wind and solar output will pose more severe challenges to the flexible operation of the system. Reasonable utilization of flexible resources and improving the flexible ramping ability of the power system will become an important means to address the challenges of new energy. This article analyzes the differences in system flexibility ramping requirements under different clearing intervals, taking into account the uncertainty of renewable energy; a two-stage electricity energy and flexible ramping market joint clearing model was established based on a stochastic programming model. By utilizing flexible resource rich regulation methods such as Wind/Photovoltaic/Energy Storage Power Station, while alleviating real-time market uncertainty, flexible ramping products were provided to improve the system's flexible adjustment ability; Finally, an example was used to study the impact of the clearing model under different clearing methods and prediction errors. The results indicate that considering the participation of Wind/Photovoltaic/Energy Storage Power Station in a two-stage market joint clearing for flexible ramping can improve the real-time operational flexibility and overall economy of the system.

Key words: uncertainty, stochastic programming models, flexible ramping products, wind/photovoltaic/energy storage power station, joint market clearing