First resonant neutral grounding implantation in Spanish distribution system

Changing the earthing system of medium voltage networks is a complex operation. It is necessary to take into account all the various technical aspects of the totality of the equipment involved in this process. Frequently, considerable additional economic investment is required as a result of this analysis of technical aspects. However, there are good reasons for reconsidering this possibility when such important aspects as personal safety and quality of the power supplied to the and consumers are considered. The SIRES research project "Earthing in medium voltage networks using resonant systems", developed by the electrical utility Iberdrola SA and the Electrical Engineering Department of the University of the Basque Country, marked the beginning of the studies and developments required for changing the earthing system in a Spanish MV network. On this distribution system, the existing solid earthing connection has been replaced with a Petersen coil.