LOSS-OF-MAINS PROTECTION - STILL AN ISSUE WITH DISTRIBUTED GENERATION

Connection of distributed generation makes power systems more complicated. This paper summarises the most important potential consequences to power system protection that have to be taken into account when connecting distributed generation (DG) into distribution networks. Both MV and LV networks are discussed, and possible solutions to the protection problems are suggested. Most of the problems caused by DG can be solved by traditional means, but there is one exception. There seems to be no satisfying solution to the Loss-of-Mains (LoM) protection. In this paper the importance of LoM protection is discussed. As a solution to the problem this paper introduces and argues for a universal, power line signalling based LoM method.