Study On Interdependent Network Vulnerability Assessment For Integrated Energy System

Integrated Energy System(IES)focuses on the coordination of various energy sources,such as electricity,heat,cold,gas and traffic.The development of IES is of great significance for improving energy efficiency,promoting the development and utilization of renewable energy,improving the utilization ratio of national infrastructure and the safety of energy supply.Traditional researches on the IES mostly focus on the modeling,simulation,planning,optimization,and operation control of the system,and the evaluation of the vulnerability of integrated energy systems is less.However,vulnerability assessment has great impact on the reliability of the energy supply of the IES and operation of the system.It is of great significance for comprehensive and accurate vulnerability assessment of IES.Under the support of the National Natural Science Foundation of China,this paper considers the possibility of island survival in IES,the status quo of hierarchical grid divisions and the heterogeneity of network nodes.The vulnerability of IES is evaluated from all levels based on the theory of interdependent networks.The research are as follows:(1)The interdependent network model of IES is built.Based on the research of complex network theory,the necessity of introducing interdependent networks into the vulnerability assessment of IES is described,and the dynamic impact relationships and coupling element models of IES represented by electricity/gas are deduced to prepare for the vulnerability assessment.(2)The general framework of vulnerability assessment of IES based on interdependent network theory is proposed.From the perspective of complex networks,the network characteristics indices and vulnerability assessment indice of IES are proposed,and the validity of the proposed framework and indicators is verified in the IEEE 39-node gas/electricity coupled model.(3)The vulnerability assessment method considering the characteristic of IES is proposed.A new indice-tree-coritity is proposed to assess the vulnerability of IES.The combination of tree-coritity and the theory of interdependent networks is beneficial to overcoming the shortcomings of traditional indices that ignore the possibility of island survival and improving the accuracy of vulnerability assessments.Considering the current situation of stratified partition in China’s power grid,the power grid has community characteristics and analyses the vulnerability of IES at the community level.It is conducive to block management of the grid and reduces the computational complexity.Considering different importance of nodes in IES due to different topological locations and tasks,this paper does further research on vulnerability assessment of IES considering node heterogeneity and power flow to accurately evaluate the impact of different nodes failure on vulnerability.In summary,this paper proposes a multi-angle and multi-aspect assessment method for the vulnerability assessment of IES,which provides a strong theoretical basis and technical support for the safe and stable operation of IES.