ASPAS Project (Automation for zone protection and control)

ASPAS Project (Automation for zone protection and control)

The purpose of the ASPAS project was to research and analyse a new way to design control and protection automation routines for the transmission network (RAS: Remedial Action Schemes) capable of creating logic for contingencies on the transmission grid, improving on the action times and reliability of the current designs, which would improve the operation and security of the system.
Proyecto ASPAS


The Spanish transmission power system includes a submarine high-voltage direct current (HVDC) link laid in the Mediterranean Sea that connects the island of Mallorca to the Spanish mainland. Due to the HVDC technology used, the operation of the link requires a minimum short-circuit power at the connection points to the alternating current network.

If this value is considered low, in the absence of system like ASPAS, the power transmitted over the HVDC link must be reduced to ensure the stability of the Electrical System. ASPAS considerably increases the precision and speed of the calculation of this minimum short-circuit power, which makes possible to increase the energy exchange over the HVDC link between the Peninsula and Mallorca, without compromising the security of the system and, therefore, maximising the economic benefits of the interconnection.


The project was launched in 2016 and concluded in November 2018.

In collaboration with

Siemens and General Electric collaborated with Red Eléctrica on the project.

Benefits for the electrical system

The increase in energy exchange between regions with different prices translates directly into economic benefits. Based on the estimates of the additional energy transmitted by the Peninsula-Balearic Islands link, thanks to the ASPAS project, and the average differential price between the energy market on the Peninsula and in the Balearic Islands, the estimated savings generated by the project totals 250,000 euros/year.

The HVDC link supplies approximately 20% of the energy demands of Mallorca through Spain's peninsular electrical system, which makes it possible to reduce the amount of energy generated by the local power plants in Mallorca. As long as Iberian energy mix is more decarbonized than Mallorca’s one, the implementation of ASPAS also reduces overall CO2 emissions, resulting in a more ecological energy supply. The CO2 savings that can be attributed to ASPAS totals 14,583 tonnes of CO2 per year.