HVDC and Facts in Power System

The development of electrical power supplies began more than hundred years ago. At the beginning stage, there were only small DC networks within the local boundaries, which were able to cover of industrial plants. An increasing demand on energy, technology changed to be transmitted from DC to AC power and voltage levels. The driving force for the development of power systems is the increase of electrical power demand. Therefore, power system developed from the regional to national systems. To achieve technical and economic advantages, extend further to large continental systems by applying interconnections to the neighbouring systems. This paper will treat benefits of HVDC and FACTS devices applied in power systems such as increased power transmission capability, improved static and dynamic stability, an increase of a availability and a decrease of transmission losses by using power Electronics techniques.