Incorporating gas pipeline leakage failure modes in risk evaluation of electricity-gas integrated energy systems

In order to incorporate the gas leakage failure in the EGIES risk evaluation, a multi-state Markov state transition model considering gas pipeline leakage is creatively developed, and the analytical formulas to calculate the involved transition rate parameters in this model are derived. The concept of virtual gas load is presented to reflect the impacts of gas pipeline leakage on the operation of natural gas network, and then the EGIES network analysis model considering the virtual load nodes is presented. A bi-level sampling method based on the mixed sequential and non-sequential Monte Carlo simulation is proposed to simulate the chronological and non -chronological aspects of EGIES simultaneously. The load curtailment based EGIES risk indices, including the gas leakage risk indices, are also designed. An EGIES with a modified RBTS and a 7-node gas system is used to demonstrate the application of the proposed method. The results indicate that pipeline leakage failures have significant impacts on the reliability of EGIES. Ignoring pipeline leakage failures in the risk evaluation of EGIES will result in an overly underestimation of system risk.