In order to validate the service restoration plans for the peninsular electricity system, as well as those of joint support of the Spanish system with the Portuguese and French systems, the operators of the three countries have carried out an international restoration exercise in the continental European system. In addition to Red Eléctrica de España (REE), Redes Energéticas Nacionais (REN), from Portugal, and Réseau de Transport d'Électricité (RTE), from France, fifteen generation and distribution companies took part in the simulation, as well as the National Centre for Critical Infrastructure Protection of the State Department for Security, the Guardia Civil (Civil Guard), the National Police and the police from the Basque and Catalan autonomous regions.
A serious incident occurs at 9:00am in La Mudarra substation in Valladolid wich seriously damages the equipment in the facility and causes a widespread zero voltage condition that affects the entire peninsular electricity system with a potential impact on the southwest of France. As of that moment, Red Eléctrica de España, with the collaboration of REN and RTE, activates the general process for the restoration of the electricity supply based on 'electrical islands' created around those generating units with black start capability. In particular, the simulation consists of the task of recovering the following zones: Aragon-Catalonia, Galicia-Leon, Asturias-Cantabria, the Duero-France axis as well as the northern zone of the Portuguese system and the southern part of the French. In addition, the communication protocol with the security forces and bodies, both State and those of the autonomous regions, is activated. This protocol is established by the State Department for Security according to a signature with the large national electricity operators.
After the initial creation of these 'islands', the supply for the nuclear power stations is secured and the ancillary services of the first combined-cycle generating units in Barcelona are activated. In the first hour of the simulation, 2,000 MW were restored. At 2:30pm the exercise is considered over after having restored 9,360 MW and having connected 17 thermal generating units to the system, with all the implicated zones synchronized.
The simulation was carried out in the facilities of the Red Eléctrica Operation School, using the training simulator, a tool which allows the behaviour of an electricity system to be modelled with great precision, reproducing the exact same system on which the operators work, and accurately recreate any incident in the national grid.
The robustness and reliability of the Spanish electricity system, in which few incidents occur, limit the possibility that the operators might have to face extremely complicated situations. For this reason, Red Eléctrica regularly carries out simulations, in order to improve processes and to reduce, as far as possible, the time necessary to restore the system.