Optimal collaborative expansion planning of integrated electrical and natural gas energy systems

The coupling between an electrical power system and a natural gas system has ever been strengthened with the increasing capacities of natural gas power generation and the development of power to gas (P2G) technology in recent years. New challenges are then introduced to the expansion planning of these energy systems due to the interconnections, since the natural gas or other energy systems are generally not included in the existing planning models for electrical power systems. Given this background, considering the characteristics and requirements of integrated energy systems, an expansion planning model is proposed. First, a linearized model of an integrated energy system is proposed. The optimal expansion planning model is then presented with an objective of minimizing the total costs of the integrated energy system, including investment, operation and reliability costs, while considering the constructions of transmission lines, gas pipelines, natural gas-fired generation plants (NGFP) and natural gas supply stations (NGSS). A highly efficient solver, MATLAB/YALMIP/GUROBI, is next employed to solve the developed optimization model. Finally, an integrated energy system including a 54-node electrical power system and a 19-node natural gas system is employed to demonstrate the proposed planning model.