Piecewise Linearization and Linepack in Operation of Integrated Electricity and Gas Systems

Integrated energy systems can be used to investigate the interdependencies in electricity and gas systems interconnected by natural gas turbines and Power-to-Gas facilities. Due to the complexity of these models, different simplifications have been proposed in the literature. Piecewise linearization is one way to improve computational expense. In this paper, a model of an integrated energy system is presented. Different methods to perform the piecewise linearization are applied to a case study. The methods are investigated in the integrated energy system regarding their performance, especially their solving time. In addition, the level of detail of the piecewise linearization in correlation to the formulation of the gas system is investigated. It is found that the incremental and multiple choice models are the best performing models for piecewise linearization. The solution could be found using the base convex combinations model within considerably more time. Other approaches to piecewise linearization did not lead
to the optimal solution in adequate time. The results show that the increase of inearization segments increases the computation times drastically due to the increase in binary variables. ... mehrFurthermore, the inclusion of linepack in the formulation increases the computation time considerably.