Dynamic energy flow analysis of integrated gas and electricity systems using the holomorphic embedding method

Abstract

To perform efficient simulation of the integrated gas and energy system’s operation and explore the interaction between natural gas and electric power, an energy flow analysis tool with high accuracy and computational efficiency is needed. The commonly used steady-state analysis method is not applicable in computing the pipeline dynamics of natural gas networks, and it is computationally expensive for most transient analysis methods to obtain high-resolution solutions. In addition, conventional methods generate energy flow profiles at pre-set time intervals, which are not compatible with continuous-time applications. To bridge these gaps, this paper proposes a dynamic energy flow analysis method applied in integrated gas and electricity systems using the holomorphic embedding method. The system’s state equations are formulated using ordinary differential equations based on a simplified natural gas network model and are reconstructed by time-embedded holomorphic functions. By solving these functions, the continuous-time profiles of the energy flow of the whole system can be readily generated with a moderate computational burden, and the pipeline dynamics can be addressed. The simulation results of the case studies validate the improved computational performance of the proposed method over that of a conventional ordinary difference equation solver. In both small-scale and large-scale cases, the proposed method can capture the transient process in every state variable in response to disturbances accurately and efficiently.