Distributed dispatch of non-convex integrated electricity and gas systems considering AC power flow and gas dynamics

The coordinated operation of the integrated electricity and gas system (IEGS) produces significant economic and environmental benefits. This paper adopts the non-convex alternating current (AC) power flow and dynamic gas models to characterize the IEGS accurately and uses an improved decomposition-coordination interior point method (IDIPM) for efficient distributed solution of non-convex IEGS dispatch problems. Different from the conventional distributed algorithms, the decomposition-coordination interior point method (DIPM) is mathematically equivalent to the centralized interior point method (CIPM), which guarantees the local convergence of the non-convex distributed optimization. We improved the DIPM by modifying the Newton matrix and using Schur complement and matrix decomposition, making its solution speed faster than the DIPM and CIPM. Furthermore, the IDIPM avoids the numerical problem caused by the DIPM and is therefore more robust. The effectiveness of the IDIPM-based distributed dispatch method is verified by numerical tests on two IEGSs of different scales. In the best case, the efficiency of the IDIPM can be increased to 4 times that of the traditional CIPM.