Abstract
Electrical distribution systems are facing new challenges mainly due to the growing penetration of distributed generation of mainly intermittent nature such as wind and solar PV. As a result, these systems need to undergo massive transformations in terms of operational scheme. In other words, new operational strategies, which increase the flexibility of distribution systems, have to be put in place. This is highly required if distribution systems are to support large quantities of variable RES power. One plausible strategy worth considering relates to the meshed operation of such systems. The main topic of this paper revolves around the prospects of operating distribution grids in a meshed manner. The benefits are quantified in terms of added flexibility to the system, and vRES utilization levels. A mixed integer linear programming model is employed to perform the required analysis, and a 119-bus distribution system is used for this purpose. The analysis of the results generally shows the strong viability of the new operation strategy in terms of adding flexibility and scaling up the utilization level of variable RES power in the considered system. This strategy can be considered as a viable flexibility option that enables further integration of intermittent power sources.

Abstract
This paper presents an extensive analysis in relation to transforming electric distribution networks in order to accommodate large quantities of variable renewable energy sources (vRESs). For this purpose, a multi-stage and stochastic mixed integer linear programming (S-MILP) model is employed. The algebraic model developed optimally allocates energy storage systems (ESSs) along with an optimal dynamic distribution network switching. For the analysis, a standard IEEE 119-bus distribution network system was used as a case study. Test results reveal that the joint optimization of ESSs and network reconfiguration markedly increase flexibility in existing systems, leading to an increase in the levels of renewables integration and utilization. Moreover, the analysis of the results shows the prospect of such systems in going fully "carbonfree", i.e. with vRES power entirely meeting system demand. Generally, the current work demonstrates that a more effective integration and utilization of large-scale vRESs is possible when existing systems are equipped with enabling technologies that are already commercially available.

Abstract
Distributed Smart Systems (DSS) should operate and restore discontinued service to consumers. In order to the system gain theses ability it is necessary to replace the manual switches for remotely controlled switches, improving the system restoration capability having in view the Smart Grids implementation. This paper aims to develop a new model, determining the minimal set of switches to replace in order to automate the system, along with a senility analysis on the position of the new switches, whether it should be placed in the same place as the manual switch or in a new location. The optimization of the system is made considering the renewable energy sources (RES) integration in the grid and energy storage systems (ESS), simultaneously, in order to improve the system reliability. The computational tool is tested using the IEEE 119 Bus test system, where different types of loads are considered, residential, commercial and industrial.

Abstract
Electrical distribution system operators (DSOs) are facing an increasing number of challenges, largely as a result of the growing integration of distributed energy resources (DERs), such as photovoltaic (PV) and wind power. Amid global climate change and other energy-related concerns, the transformation of electrical distribution systems (EDSs) will most likely go ahead by modernizing distribution grids so that more DERs can be accommodated. Therefore, new operational strategies that aim to increase the flexibility of EDSs must be thought of and developed. This action is indispensable so that EDSs can seamlessly accommodate large amounts of intermittent renewable power. One plausible strategy that is worth considering is operating distribution systems in a meshed topology. The aim of this work is, therefore, related to the prospects of gradually adopting such a strategy. The analysis includes the additional level of flexibility that can be provided by operating distribution grids in a meshed manner, and the utilization level of variable renewable power. The distribution operational problem is formulated as a mixed integer linear programming approach in a stochastic framework. Numerical results reveal the multi-faceted benefits of operating distribution grids in a meshed manner. Such an operation scheme adds considerable flexibility to the system and leads to a more efficient utilization of variable renewable energy source (RES)-based distributed generation.

Abstract

Abstract
A large quantity of variable renewable energy sources (RESs), most notably wind and solar, is now connected to the Portuguese network system, which makes it somehow unique. Yet, in the coming years, the network is expected to accommodate more of these and other technologies of "clean" power productions. The deployment and efficient utilization of various flexibility options are certainly required in a system experiencing such levels of dynamic changes so as to ensure a standard level of service provision in terms of security, stability and reliability. Among these is a battery energy storage system (BESS), which is emerging as one of the most viable and effective options of increasing the much-needed flexibility in power systems. This work aims to assess the impact of deploying BESSs on the operational performance of the Portuguese transmission grid, mainly in terms operational flexibility and variable RES power support. In particular, the potential benefits of strategically placed BESSs are investigated using a stochastic optimization framework. Numerical results show that integrating BESSs leads to a more efficient use of renewable power by considerably minimizing curtailments, and a 10% reduction in system-wide cost. Energy losses are moderately increased as a result of the BESS deployment. But this is offset by the savings in operation and emission costs.