Fault assessment method of Integrated Electricity and Natural Gas Network Considering Interdependent Characteristics

Abstract

As the coupling between the power grid and the natural gas network continues to deepen, the interdependence between the power grid and the natural gas network has caused new system safety operation problems, increasing the risk of cascading failures in integrated electricity and natural gas system. For this reason, this paper proposes a method to analyze the influence of fault propagation in integrated electricity and natural gas system considering the interdependence of the power grid and the natural gas network. First, it analyzes the interdependence characteristics of integrated electricity and natural gas system and the propagation mechanism of faults between the two networks; and then analyzes the propagation characteristics of faults between the two networks under different coupling degrees. Furthermore, the quasi- steady-state power flow equations of integrated electricity and natural gas system considering the slow time-scale characteristics of transmission of natural gas is constructed. And then, from the perspective of energy supply efficiency and reliability of system, this paper uses loss rate of load and loss rate of global network effectiveness indicators to evaluate and analyze the impact of failure propagation on operation of integrated electricity and natural gas system, which constructs the assessment model of cascading failures of integrated electricity and natural gas system. Finally, the validity and applicability of the proposed model method are verified by simulation examples.