Self-Healing Grid Algorithm for Flood-Resilient Power Distribution

Solution Overview

Barcelona has implemented a self-healing algorithm within its electrical distribution grid as part of a comprehensive flood impacts reduction strategy.[1] Spanish DSO Endesa is advancing investment in the ongoing upgrading and digitalisation of Barcelona's electricity infrastructure to transform it into the 'digital city of the future'.[2] This approach represents one of seven key measures designed to enhance urban resilience against flooding events, working alongside improvements to surface drainage, sewer system capacity, sustainable urban drainage systems, early warning systems, and waste container stability measures.[1]

Technical Components

The Location of Breakdowns and Restoration of Supply (LARS) system serves as an essential feature of this digitalisation process, enabling more rapid and accurate determination of line incidents and reactions to them.[2] The LARS system integrates historical data, maps of street works and weather forecasts to more accurately and quickly determine where on a line an incident has occurred and react more quickly.[3] Endesa is creating a Network Digital Twin for Barcelona, an exact digital replica of the existing network that can be used to generate simulations in all possible conditions, control component operation in real time, carry out preventive maintenance, and interact with field operators.[3] The digital twin enables the location of a potential fault in the grid to be detected, assisting prevention, and the most efficient way to restore supply in the event of an extreme weather event to be simulated, helping to reduce restoration times and improve customer service quality.[8] The modeling of the Barcelona electrical system in RESCCUE was carried out based on heavy historical rains, the flooding of the rivers and the sea.[4] As part of the automation of the MV grid, new remote control systems are planned, which should enable quicker location of faults and the ability to manage the network without the need to send out personnel to the location.[2]

Implementation Details

By the end of 2023, 74% of Barcelona's transformer centres were due to be sensorised as part of Endesa's grid modernization plan.[3] The remote control of 321 transformer centres was planned in Barcelona as part of the City Plan.[3] By the end of 2023, 40% of the installations were expected to be automated.[2] In the current year, Endesa expects to invest €46 million ($50 million) in Barcelona's grid digitalisation.[2] The main implementing actors for improving the resilience of Barcelona's electricity grid are Ajuntament de Barcelona (Urban Ecology), Endesa, and Red Eléctrica de España (REE).[5] Through RESCCUE, Endesa can simulate possible contingencies and cascading effects in any of the potentially flooded electrical installations including primary substations, secondary substations and their interconnections.[4]

Benefits and Impacts

The automation and digitalisation of Barcelona's electricity grid will enable a 20% reduction in the time clients are affected by an issue, whatever may be the cause.[3] The self-healing algorithm objective is to minimize the load unsupplied after a fault event in the distribution grid.[9] Endesa's role focuses on quantifying the impact of climate change on the capacity to recover power supplies and the interaction of this with the water cycle.[7] The project will analyse the improvements smart grids and, specifically, micro-grids (small-scale systems that combine power generation, storage and distribution) can make to the resilience of cities.[7]

Climate Adaptation Relevance

This system directly addresses climate-related electrical grid vulnerabilities from multiple flooding sources. In Barcelona, the impact of climate change has been established to be an increase of 7–26% at peak rainfall intensity, depending on rainfall duration.[10] The impact of atmospheric discharges on medium voltage lines generates overvoltages which can produce interruptions in the supply of energy and damage to electric infrastructures.[4]