Research On Assessment Method Of Supply Resilience Of Natural Gas Supply System

The safe and stable supply of natural gas is of great significance to social stability and economic development.Natural gas supply system consists of many units,the network topology is complex,and the natural and social environment in which it is located is complex.All this makes it a huge challenge to ensure the supply safety of natural gas supply system.In response to this problem,this study introduces the concept of resilience,and determines the anti-interference ability and recovery ability of natural gas supply system after disturbance as the core connotation of the system’s natural gas supply resilience.On this basis,the natural gas supply resilience evaluation method is proposed from three aspects: network topology,system dynamics and operating state uncertainty.Firstly,in view of the complex network topology structure of natural gas supply system,a network modeling method of natural gas pipeline network based on complex network theory is proposed,and the complexity and evolution mechanism of natural gas pipeline network are analyzed.The evaluation index and calculation method of supply resilience of natural gas pipeline network based on topology structure are proposed.The analysis of examples shows that this method can evaluate the supply resilience of complex pipe network systems in the face of different types of disturbances,and quantitatively evaluate the influence of topology structure on the anti-interference ability and recovery ability of natural gas pipeline network.From the perspective of pipeline network topology design and optimization,this method can provide theoretical support for improving the supply resilience of natural gas pipeline network.In view of the highly complex structural and dynamic characteristics of natural gas supply system,this study established an evaluation method for supply resilience of natural gas supply system from the static and dynamic perspectives by introducing the ecological network analysis method.Among them,the static analysis method of natural gas supply resilience includes system structure analysis,flow analysis and utility analysis;the dynamic analysis method comprehensively evaluates the anti-interference ability and recovery ability of natural gas supply system.The analysis of examples shows that this method can quantitatively characterize the key system characteristics that affect the supply capability of natural gas supply system,and comprehensively and systematically evaluate and analyze the supply resilience of natural gas supply system.Aiming at the high uncertainty of the operation state of natural gas supply system,this study firstly established the uncertainty representation model of each component of natural gas supply system by combining the failure mechanism model and the statistical analysis model.Then,the uncertainty-driven operating state evolution model of natural gas supply system is established based on the Markov model.Coupling stochastic simulation,network flow theory and optimization algorithm,an efficient calculation method of system’s natural gas supply capacity based on stochastic evolution of operating state is established.Finally,evaluation indicators are established from the perspectives of global gas supply resilience and consumer gas supply resilience which can quantify the supply resilience of natural gas supply system in the face of different accident disturbances.