A unified model for transient flow analysis of the integrated electric power and natural gas system with multiple time scales

The electric-gas coupling integrated energy system provides an effective way to improve the operation flexibility of IES and the consumption capacity of renewable energy resources. It is very hard to achieve due to the different characteristics between the power and gas system in aspects of control mechanism, network topology and dynamic process. To solve this problem, both a unified model of the transient energy flow and an algorithm for solving this unified model are proposed for the first time in this paper, combining the dynamic modeling of the electric-gas network and the singular perturbation theory. Moreover, in the unified model, an improved model of the gas turbine is designed for capturing the energy interactions of electric-gas networks and meeting the calculation need of multiple time scales simultaneously. Simulation results show that the transient information can be acquired under disturbances of any time by solving the unified model.