Controllability Robustness Of Complex Chemical Networks Based On Dynamic Cascade Failure Model

In a complex network of chemical process systems,the failure of a node may trigger cascade failure,which may lead to the failure of the whole production process.In order to improve the resistance of chemical networks to failures,previous research has developed cascade failure models to describe the controllability robustness of chemical networks after cascade failures,but in previous studies,the nonlinear and dynamic characteristics of actual networks were not considered.Chemical networks have complex internal structures,strong correlation among variables,and are generally dynamic in nature.Therefore,this paper proposes an analysis method and optimal design of controllability robustness of chemical networks based on dynamic cascade failure model,which provides a theoretical basis for improving the ability of chemical networks to resist cascade failure.Firstly,based on the complex network theory,the complex network model of chemical process system is constructed by abstracting the variables and the relationship between variables in the chemical process as the nodes and edges of the network and defining the adjacency matrix according to the topological relationship of the chemical process system.Secondly,the initial load of each node is solved according to the chemical complex network model,and three different complex network cascade failure models are constructed based on the commonly used model of linear load-capacity and the more realistic nonlinear load-capacity,using the initial capacity redistribution strategy and the residual capacity redistribution strategy,respectively.Then,a dynamic cascade failure model based on the nonlinear load-capacity model and residual capacity redistribution strategy is established based on the dynamic characteristics of node loads in real chemical process systems,and a better cascade failure model is derived by comparing with the non-dynamic cascade failure model.And considering the influence of neighboring nodes of overloaded nodes,a local protection strategy by dynamically adjusting the capacity of overloaded nodes is proposed to enhance the controllability robustness of chemical networks when suffering from cascade failure.The validity and feasibility of the cascade failure model based on the load-capacity model are verified through case studies,and the controllability robustness of the chemical network is enhanced with the increase of the load and capacity parameters.The local protection strategy based on the dynamic cascade failure model effectively improves the controllability robustness of the chemical network and provides a theoretical reference for improving the controllability robustness of the actual chemical process system in response to cascade failure.