Optimal Operation of Integrated Electricity-Gas Systems for Renewable Energy Accommodation Considering Flexible Resources

With the rapid development of wind power and photovoltaic power generation, it has become a major trend to establish an energy system centered on high proportion of renewable energy all over the world. Intermittence and volatility are the main features of renewable generation, which has brought challenges to the security and flexibility of energy system's operation. Making full use of the regulating capacity of flexible resources can effectively adapt to the stochastic characteristics of renewable generation and improve the renewable energy accommodation capacity. Considering the advantages of flexible resources such as flexibly reformed thermal power units, gas-fired units and electrical energy storage in the aspect of flexibility regulation, a day-ahead scheduling model of integrated electricity-gas systems for renewable energy accommodation is proposed. Firstly, the flexibility of the power system is quantified by the insufficient flexibility reserve capacity, which characterizes the renewable energy accommodation capacity of the system. Then, the economy of each flexible resource is investigated from the point of the total operation cost. Finally, the factors affecting the operation cost are analyzed. Case studies demonstrate the feasibility and effectiveness of the proposed models.