Reliability Evaluation of IEGS Considering Multi-States Leakage of Pipelines

With the widespread use of distributed gas-fired power generators and Power-to-Gas(P2G) equipment, the coupling between natural gas networks and power systems is increasing. A gas pipeline leak failure poses a significant challenge to the reliability of the Integrated Electricity-Gas Systems (IEGS). This paper proposes a reliability evaluation method for the IEGS under the gas pipeline leakage model: First, a Markov model is used to describe the state transition probabilities of different severities of pipeline leaks, then the pipeline failure rate model is obtained. Next, a virtual pipeline model is used to describe the impact of pipeline leaks on the gas network power flow and the gas storage. Due to the non-convexity of the gas network power flow, which increases the difficulty of solving the model, a Taylor expansion is employed to linearize the Waymouth equation. Finally, Monte Carlo simulation is used to evaluate the reliability of the electrical-coupling system under pipeline leakage. Through numerical examples, it is shown that the pipeline leakage at different severities has a significant impact on the reliability of the electrical-coupling system. Ignoring the pipeline leakage may lead to overly optimistic evaluation results.