Security region of natural gas pipeline network system: Concept, method and application

摘要

This paper proposes the security region of natural gas pipeline network system (NGS-SR), which provides a new perspective to analyze the security of the system. Firstly, the definition of NGS-SR is proposed, that is, the closed set of all secure operating points in the state space. NGS-SR is then modeled considering variety of operation constraints, such as the hydraulic balance constraint, the node gas pressure constraint, etc. Secondly, an observation-based method is proposed to solve the security boundary of NGS-SR. Thirdly, the approaches of security assessment and preventive control based on NGS-SR are illustrated. Finally, the NGS-SR of two typical systems are observed, analyzed and compared with the existing methods of security analysis. The results show the validity and precision of the proposed model and method, as well as the advantages of NGS-SR: 1) NGS-SR can describe the secure operating range of the system in a geometric and visualized way; 2) NGS-SR is beneficial to realize online security analysis, the analysis speed is increased up to 1944 times in the cases; 3) NGS-SR can provide the security margin information for system operation. (C) 2020 Elsevier Ltd. All rights reserved.