Online Control of Islands Microgrids Connected by Electrical Submarine Cable

Abstract

The present paper introduces a description of the use of online systems for real-time monitoring, control and management of power grids. Following the Smart Fossil Free Island project, which aims to make Porto Santo Island an intelligent, self-sustaining, and free of harmful gases emissions Island, or, in other words, to produce energy without using fossil fuels, arises the possibility to interconnect the electricity grids of Madeira and Porto Santo Islands through a submarine high voltage cable. This is an innovative project, since it intends to interconnect two isolated microgrids from two Islands with small dimensions, through a submarine electric cable installed at about 2300 m depth. This allows to partially or totally power Porto Santo Island electrical grid from the electro producing system of Madeira Island. In order to analyze the viability of this connection, a comparative study between a High Voltage Alternating Current (HVAC) system and a High Voltage Direct Current (HVDC) system has been carried out. The client impositions require a bidirectional system, given the possibility of installing, on Porto Santo Island, a wind farm able to power this Island and transfer a considerable percentage of the electric energy needed to power Madeira Island. This project uses online systems to monitor, manage and control the frequency, voltage, active and reactive power of the two Islands from Madeira, regulating the transfer of power between them, in order to ensure the continuity of service and all parameters of electrical quality.