A high-accuracy model of gas network for dynamic analysis of electricity-gas energy flow

Abstract

Accurate simulation of the dynamic energy flow is crucial for the reliability and economics of the integrated electric and gas systems (IEGS). In order to simplify the complex partial differential equations (PDEs) in the gas dynamics, previous studies have typically approximated the flow coefficients in the PDEs as fixed values. However, the flow coefficients vary significantly with the operating state of the IEGS, and ignoring this variation could lead to inaccurate modeling. In this paper, the expression for the flow coefficients is derived and the gas dynamics PDEs are transformed into variable coefficient partial differential equations (VC-PDEs). To solve the proposed VC-PDEs, a three-stage leapfrog finite difference method (TL-FDM) is developed, which updates the flow coefficients in real-time during the solution process, thus enabling high-accuracy simulation of the gas flow model. The consistency and stability of the proposed model are proven theoretically. In addition, an IEGS optimal scheduling model is developed based on the proposed dynamic gas flow model, and the improvement of system flexibility and reliability through high-accuracy gas flow simulation is quantitatively analyzed. Case studies demonstrate the accuracy and efficiency of the proposed model in different systems.