Resumen de Optimal security-constrained model for the integrated power and natural-gas system
The increment of gas-fired units has resulted in a growing dependence on natural gas as a primary fuel for electricity generation and thus a higher level of integration between power and gas networks. On the one hand, the reliability of power systems has been affected since interruptions in the fuel supply may lead to a loss of multiple electric generators. On the other hand, gas systems are facing higher volatile and difficult to forecast demands, especially because gas-fired units are being dispatched as operating reserves to back up intermittent renewable generation, demand deviations, and/or contingencies.
Although several models have been developed for studying the power system reliability, there are few contributions regarding the consideration of gas network constraints into the decision process and with respect to the reliability of gas systems. Given the high level of interdependence between energy sectors, power system security studies that do not include gas network constraints could overestimate the fuel delivery capability required to fulfill power system requirements in normal and disturbed conditions. Furthermore, the lack of reliability analysis in gas networks is a potential risk to the operation of both energy infrastructures. The current level of integration implies that the reliability of one system depends not only on its own components but also on the reliability of the other system.
As a result, this thesis aims to develop a method to perform preventive security analyses of an integrated power and natural gas system in the short-term operation. In order to do so, this research first details how to model and solve efficiently and accurately the short-term operation of gas and power networks independently. Afterwards, different methods are proposed to integrate those energy systems in order assess the reliability of the coupled network in such a way that adequate levels of adequacy and security are preserved. The security of the integrated grid is accomplished by including transmission network contingencies from both systems in the optimization problem, and the energy adequacy is studied by modeling the gas dynamic (travel velocity and compressibility). Obtained results show how the supply adequacy of the natural gas transmission network is critical to the security and feasibility of electric power generation.
