Abstract
The integration of distributed Battery Energy Storage Systems (BESS) at the Medium Voltage (MV) and Low Voltage (LV) networks increases the distribution grid flexibility to deal with high penetration of Renewable Energy Sources (RES). In addition, it also enables the deployment of key self-healing functionalities, which allow the islanded operation of small sections of the distribution network. However, new planning and real-time operation strategies are required to allow the BESS coordinated control, as well as a cost-effective and stable operation. This paper presents new tools developed for the planning and real-time operation of distribution networks integrating BESS, particularly when operating islanding. For real-time operation, a short-term emergency operation-planning tool assesses the feasibility of islanded operation of a small section of the distribution network. The long-term impact of a BESS control strategy for islanded operation is assessed through a Life Cycle Analysis (LCA) tool. The results and implementation experience in real distribution network are also discussed. © 2020

Abstract

Abstract
The large scale integration of inverter-based renewable generation in isolated power systems is posing stability concerns as a result of the displacement of the conventional synchronous machines (SM). In this sense, the integration of battery energy storage systems (BESS) connected to the grid through power converters operating as grid-forming units is mandatory in order to ensure system stability. Therefore, this paper aims to perform a dynamic stability analysis of an isolated power system regarding the installation of a BESS, where it is intended to determine the minimum required grid-forming power capacity of the associated power converter that guarantees system stability under several operational scenarios. Moreover, the expected interactions between the grid-forming inverter and the conventional SM are also addressed. © 2019 IEEE.

Abstract
A distinctive characteristic of a Microgrid (MG) system is related to the ability of operating autonomously. However, the stability of the system relies in storage and generation availability, providing frequency and voltage regulation. Considering the deployment of distributed storage units in the Low Voltage network and of smart metering infrastructures, this paper presents an online tool for promoting an effective coordination of MG flexible resources in order ensure a secure autonomous operation and maximize the time that the MG is able to operate islanded from the main grid. The tool determines a priori an emergency operation plan for the next hours, based on load and microgeneration forecasting. The limited energy capacity of the distributed storage units participating in MG control is also considered.

Abstract
Reliable and smart information on the flexibility provision of Home Energy Management Systems (HEMS) represents great value for Distribution System Operators and Demand/flexibility Aggregators while market agents. However, efficiently delimiting the HEMS multi-temporal flexibility feasible domain is a complex task. The algorithm proposed in this work is able to efficiently learn and define the feasibility search space endowing DSOs and aggregators with a tool that, in a reliable and time efficient faction, provides them valuable information. That information is essential for those agents to comprehend the fully grid operation and economic benefits that can arise from the smart management of their flexible assets. House load profile, photovoltaic (PV) generation forecast, storage equipment and flexible loads as well as pre-defined costumer preferences are accounted when formulating the problem. Support Vector Data Description (SVDD) is used to build a model capable of identifying feasible HEMS flexibility offers. The proposed algorithm performs efficiently when identifying the feasibility of multi-temporal flexibility offers.