We propose a modeling framework and computational method to examine the impacts of operational contingencies on a pipeline system’s capacity to transport natural gas, and study the resulting effect on the reliability of an electric power transmission system that relies on that pipeline for generation fuel. A stochastic model is used to simulate the prevalence of unplanned events that lead to outages that decrease transport capacity, and that may cause curtailments to gas-fired generators that do not hold firm pipeline transportation contracts. We use a transient optimal gas flow as an integrated model that serves as a proxy for pipeline financial and physical operations that involve human-in-loop decisions including compressor setpoint changes. The resulting effects on energy delivery by both the electric power and natural gas sectors is evaluated using transient pipeline simulation and power flow analysis. We consider contingencies occurring during normal operations and collect statistics related to pipeline performance. The proposed approach can be used to discover system vulnerabilities and could ultimately guide development of reliability standards.
Many electric power systems throughout the world now heavily rely on natural gas pipeline networks to supply fuel for gas-fired generation [1]. This has led to growing demand for natural gas transportation in large-scale pipelines, but also increased variability and intermittence in high volume gas flows to dispatched gas-fired generators, which result from operational decision making for the power grid. Although the wholesale power and gas delivery sectors have taken actions to improve market efficiency and implement formal coordination mechanisms [2], [3], it is becoming increasingly problematic for power generation asset managers to procure natural gas during periods of pipeline congestion for both base load and ancillary services [4], which may lead to load curtailments [5] such as during the recent cold weather event in Texas.
