A novel analytical unified energy flow calculation method for integrated energy systems based on holomorphic embedding

Abstract

The multiple energy flow (MEF) calculation plays a key role in the operational analysis of the integrated energy system (IES). This paper proposes a novel analytical unified approach based on the fast and flexible holomorphic embedding (FFHE) method for solving the MEF problem. In the proposed approach, the power flow model of heating and natural gas networks in matrix form is established first. On this basis, the power flow equations of electrical, heating, and natural gas networks are holomorphically embedded in FFHE form, and the recursive equations of each network are determined according to the methodology of the holomorphic embedding (HE) method. By performing the modifications concerning coupling equipment, the recursive relationships of subnetworks are modified and integrated, thereby a unified HE recursive solution form is obtained to solve the energy flow of all networks uniformly. In addition, the Newton–Raphson (NR) method is used to assist in selecting the initial guess for better performance of the proposed approach. Simulation results of the test case verify the accuracy of the proposed FFHE models. Moreover, several case studies are implemented in the testing IES to demonstrate the superiority of the proposed approach in convergence and computational efficiency.