SAInt - A Simulation Tool for analyzing the Consequences of Natural Gas Supply Disruptions

The interruption of gas supply to the EU through Ukraine in January 2009 has been the largest gas crises in the EU ever. This was the triggering event to develop and finally enact Regulation 994/2010 on security of gas supply, nowadays of mandatory implementation by EU Member States (MS). According to this Regulation, MS have to develop a Risk Assessment (RA), a Preventive Action Plan (PAP) and an Emergency Plan (EP), among other obligations. The development of a RA needs the identification of a number of scenarios, and the estimation of their probabilities and consequences. In this paper, we focus our effort on the correct estimation of consequences of potential scenarios. Given the complex and dynamic behavior of national or regional gas transport systems (GTS), this estimation can only be done with an adequate gas transport network simulation model. In previous work, a mathematical engine (SAInt) was developed for simulating hydraulic transients in GTS under isothermal conditions. Nevertheless, the actual resolution of transport equations is not sufficient to simulate the degrees of freedom of a network to react to a transient or, more severe, to a gas supply disruption. In this paper, we identify the different actions that the operator, market actors and authorities may adopt in the different steps of a gas crisis and the infrastructure elements used to implement those actions (production sites - PRO, underground gas storage facilities - UGS, liquefied natural gas regasification terminals - LNG, compressor stations – CS, cross border entry points - CBE, etc.). Furthermore, we identify the different possible control modes of each facility in the gas infrastructure and implement them in SAInt to further develop its capabilities as an integrated simulation tool to analyze gas supply disruptions. Finally, we apply SAInt on a real world instance

An integrated simulation tool for analyzing the Operation and Interdependency of Natural Gas and Electric Power Systems

In this paper, we present an integrated simulation tool for analyzing the interdependency of natural gas and electric power systems in terms of security of energy supply. In the first part, we develop mathematical models for the individual systems. In part two, we identify the interconnections between both systems and propose a method for coupling the combined simulation model. Next, we develop the algorithm for solving the combined system and integrate this algorithm into a simulation software. Finally, we demonstrate the value of the software in a case study on a real world interconnected gas and electric power system of an European region. This paper was prepared for presentation at the PSIG Annual Meeting held in Vancouver, British Columbia, 11 May - 13 May 2016

Development of a Simulation Framework for Analyzing Security of Supply in Integrated Gas and Electric Power Systems

Gas and power networks are tightly coupled and interact with each other due to physically interconnected facilities. In an integrated gas and power network, a contingency observed in one system may cause iterative cascading failures, resulting in network wide disruptions. Therefore, understanding the impacts of the interactions in both systems is crucial for governments, system operators, regulators and operational planners, particularly, to ensure security of supply for the overall energy system. Although simulation has been widely used in the assessment of gas systems as well as power systems, there is a significant gap in simulation models that are able to address the coupling of both systems. In this paper, a simulation framework that models and simulates the gas and power network in an integrated manner is proposed. The framework consists of a transient model for the gas system and a steady state model for the power system based on AC-Optimal Power Flow. The gas and power system model are coupled through an interface which uses the coupling equations to establish the data exchange and coordination between the individual models. The bidirectional interlink between both systems considered in this studies are the fuel gas offtake of gas fired power plants for power generation and the power supply to liquefied natural gas (LNG) terminals and electric drivers installed in gas compressor stations and underground gas storage facilities. The simulation framework is implemented into an innovative simulation tool named SAInt (Scenario Analysis Interface for Energy Systems) and the capabilities of the tool are demonstrated by performing a contingency analysis for a real world example. Results indicate how a disruption triggered in one system propagates to the other system and affects the operation of critical facilities. In addition, the studies show the importance of using transient gas models for security of supply studies instead of successions of steady state models, where the time evolution of the line pack is not captured correctly