Modeling and Analysis Techniques for Multimodal Utility Networks

In the last years there has been a growing interest in the area of city infrastructures research, driven by the goal of reducing continuous energy usage without affecting standards of living. The more alternative energy sources and energy conversion technologies (such as solar, wind, hydroelectric power or fuel cells) are being utilized, the more dependent become utilities one from another and the more they interact and exchange resources. For instance, renewable energy is typically intermittent and it is often required to convert it into other utilities or store it for further use. Another example of interdependencies of utilities is cogeneration - production of several utilities from a single fuel. Therefore it is often necessary to maintain utility networks taking into account its interconnections with the other utility networks. In this paper we focus on the city infrastructure networks that supply buildings with utilities such as electricity or heating and consider them jointly for the analysis of interdependencies between them. A graph-based approach to represent utility networks and their interconnections is suggested. We propose different applications of a graph-theoretical model that captures not only topological structure of the city networks, but also its physical properties. Further, we propose that such graph models can be used not only in vulnerability analysis where similar graphs have been used until now, but also for other purposes, such as condition monitoring of the network or optimization control. (C) 2015 Published by Elsevier Ltd.