Power systems are undeniably considered as one of the most important infrastruc tures of a country. Their importance arises from a multitude of reasons of technical, social and economical natures. Technical, as the commodity involved requires con tinuous balancing and cannot be stored in an efficient way. Social, because power has become an essential commodity to the life of every person in the greatest part of our planet. Economical, as every industry relates not only its operations but also its financial viability in most cases with the availability and the prices of the power.