A methodology for smart grid reconfiguration

Abstract

Abstract:In this work, it is presented a methodology for the reconfiguration of smart grids that is applied to a smart grid formed by two microgrids that can be electrically interconnected in contingency situations. Each microgrid is also connected to an Electric Power System (EPS) when operating in the normal state. Moreover, the smart grid includes energy storage devices (batteries) located at strategic points. Serious faults that isolated the microgrids of the EPS and, moreover, considerably reduced the generation capacity of such microgrids are simulated. The proposed methodology is applied to reconfiguration in scenarios involving cooperation between microgrids and/or the use of energy storage devices. Performance indices are also proposed to enable a quantitative analysis for each scenario. It is shown that intelligent cooperation between microgrids and the smart-use storage energy is the best option for reducing the impacts in a contingency scenarios.Keywords: Smart grids, microgrids, grid reconfiguration, computational intelligence, genetic algorithm. IntroduçãoMicrogrids, in turn, are electric power networks with several consumer units (loads) and several strategically distributed low-power generators. Both loads and generators are located geographically close (Lasseter, 2011), allowing different manners of connection, that is, different topological changes. Thus, it is possible that for a fault event at one or more points in the microgrid, all adjacent energy sources and loads can be immediately disconnected (isolated) to prevent the problem from spreading. However, the remainder of the microgrid that is not affected by the fault should continue operating normally.Solving the problem of reconfiguration involves providing alternative ways to establish connections between loads in regions with no failures and the non-disconnected sources. Thus, reconfiguration contributes to the continuity of the power supply in contingency situations, such as the occurrence of a short-circuit (Shariatzadeh et al., 2011), and can be initiated for at least three reasons, i. e. power failure, disequilibrium in the power balance, or maintenance activities on Power network components (Cebrian and Kagan, 2010). In the first two cases, some lower priority loads are likely to be rejected, i.e. disconnected from the microgrid.In short, solving the problem of microgrid reconfiguration includes the following processes: topology changes in the microgrid; possible rejection of lower priority loads, i.e., disconnecting them from the microgrids; and maintenance of the power balance for ensuring the operational continuity of priority loads. Therefore, the main objective of this paper is to propose a reconfiguration methodology for smart grids. Literature reviewA methodology and system for automatic reconfiguration of distribution network in real time was presented in (Pfitscher et al., 2011). The authors state that the reconfiguration of distribution network can reduce losses, balance loads and improve quality indicators when in normal...