Novel Optimal Dispatch Method for Multiple Energy Sources in Regional Integrated Energy Systems Considering Wind Curtailment

Abstract

Power-to-gas technology uses temporary surplus electricity to create either renewable hydrogen or renewable natural gas, which can then be stored in natural-gas pipelines and used when needed. As a result, P2G transforms conventional one-way coupling of a power/heat/natural-gas system into two-way coupling. Furthermore, its operating characteristics makes it possible to more effectively utilize wind-power. This paper describes a new optimal dispatch model for integrated electricity/gas/heat energy systems. The model considers the effective use of surplus wind-energy with electricity-to-gas equipment. First, a multi-energy network model is built, taking into account both equipment and network constraints. Then, we apply a novel two-layer optimization method, which uses P2G, to “absorb” wind power. While the top-layer model is used for the day-ahead dispatch of the natural-gas network containing P2G, the bottom-layer model describes the day-ahead economic dispatch of the electricity/heat system, which includes wind power. Based on the Karush-Kuhn-Tucher conditions of the bottom-layer model, the two-layer model is transformed into a single-layer model, and we linearize the nonlinear equation to convert the nonlinear model into a mix-integer linear programming problem, which is solvable using the General Algebraic Modeling System. Finally, numerical case-studies are performed to evaluate the accuracy and effectiveness of the proposed method.

Keywords

• Multi-enery coupling
• power-to-gas
• two-layer optimization
• wind-power consumption