Reliability Evaluation of Integrated Electricity-gas System Considering Multiple Failure Modes and Structural Parameters Correlation of Pipeline

In the evaluation of the reliability of integrated electricity-gas system, the rupture failure of pipelines, rather than the influence of the leakage failure, are usually considered. In fact, the failure modes of the pipeline include small hole leakage, perforation and rupture; and the pipeline can still transport some natural gas in case of leakage. In addition, the pipeline parameters are usually assumed to be independent of each other in the structural reliability calculations of natural gas pipelines, and the correlation between parameters is ignored. In this paper, a reliability evaluation model of integrated electric-gas system considering the multiple failure modes and parameter correlation of pipeline is proposed. First, according to the failure mechanism of pipeline, the limit state function of pipeline is established by Mises criterion, the failure rate of the pipeline is analyzed considering the correlation of the parameters of the limit state equation of the pipeline, and the multi-state operation model of the pipeline is established according to the state transition characteristics of the natural gas pipeline. Secondly, aiming at the small hole leakage and perforation of the pipeline, a natural gas leakage model of the pipeline is established to describe the transportation capacity of the pipeline under these two derating operating conditions. Finally, a case study composed of IEEE RTS79-NGS20 system is utilized to verify the validity of the model. © 2024 Chin.Soc.for Elec.Eng.