Multi-Period Integrated Framework of Generation, Transmission, and Natural Gas Grid Expansion Planning for Large-Scale Systems

In this paper, a multi-period integrated framework is developed for generation expansion planning (GEP), transmission expansion planning (TEP), and natural gas grid expansion planning (NGGEP) problems for large-scale systems. New nodal generation requirements, new transmission lines, and natural gas (NG) pipelines are simultaneously obtained in a multi-period planning horizon. In addition, a new approach is proposed to compute NG load flow by considering grid compressors. In order to solve the large-scale mixed integer nonlinear problem, a framework is developed based on genetic algorithms. The proposed framework performance is investigated by applying it to a typical electric-NG combined grid. Moreover, in order to evaluate the effectiveness of the proposed framework for real-world systems, it has been applied to the Iranian power and NG system, including 98 power plants, 521 buses, 1060 transmission lines, and 92 NG pipelines. The results indicate that the proposed framework is applicable for large-scale and real-world systems.