Piecewise Linear Approximation of Gas Flow Function for the Optimization of Integrated Electricity and Natural Gas System

The development of integrated electricity and natural-gas energy system (IEGS) aims at improving the energy efficiency and realizing complementarity between different energy sources. However, co-optimization of the IEGS suffers from non-convex and nonlinear Weymouth equation. Focusing on the piecewise linear approximation methods of the IEGS, this paper compares with the formation, the computational speed, and accuracy of the existing piecewise linear approximation methods, and proposes a modification method that achieves both fast-processing and high-accuracy. The numeral testing results verify the effectiveness of the proposed method.