Optimal Planning of Integrated Electricity-Gas Systems with High Penetrated Renewable Energy for Flexibility Enhancement

High-penetration integration of renewable energy is the trend of power system in the future. However, renewable generation is highly volatile and intermittent, and its large-scale integration will compress the operation space of conventional units, which will bring great challenges to the operational flexibility of the energy systems. To alleviate the adverse impacts of renewable generation on system flexibility, multi-type flexibility improving measures such as the flexibility reformation of thermal power units, the construction of gas-fired units and electrical energy storage devices installation can be some effective solutions. For the purpose of flexibility enhancement to adapt high penetration of renewable energy, a collaborative planning model for integrated electricity-gas energy systems considering multi-type flexible resources is established. The planning decisions are reflected in the operation characteristics of the system, which can actually improve the operational flexibility and minimize the annual operation cost. The feasibility and effectiveness of the proposed model is verified on an integrated electricity-gas energy system.