It is very well known that alternating electrical energy can't accomulate and production ofelectrical energy must follow user requirements in every moment. Cossumtinon size is variable,and basic transmission caracteristics of electrical energy is balance between production andcosumption.Every power system is exposed to changes, because of technical reasons and increasing ofstability, economic reasons and production optimization. Interconnection between powersystems so called parallel connection in proper way, increase stability and availability ofsystems which are connected. For such a connections, a wide theorethical and experimentalpreparations are needed, which will show dinamical behaviour of systems before and afterparallel connection. This kind of connection makes possible to have more generators andcosumers inside connected systems, with possibility of exchange and reselling electrical energyand with this approach it is possible to increase efficiency of connected systems.