Rehabilitation and upgrading of 400 kV substations in order to interconnect the Romanian power system to the union for the coordination of transmission of electricity (U.C.T.E.)

The paper shows an interesting case of three 400 kV substations, ones of the most important and great substations of the Romanian power system called Portile de Fier, Tantareni and Urechesti. The strategic task of the Romanian Transmission Electricity Company - TRANSELECTRICA - is to perform in the next years (2002-2005) the interconnection of the Romanian power system to the western European countries system, well known as union for the coordination of transmission of electricity-U.C.T.E. This task is to be realized in order to increase the static and dynamic stability, and to increase the reliability of the Romanian power system. In the year of 1996 was approved by the Romanian government a loan from the European bank for reconstruction and development for acquisition of modern equipment for these substations, such as: circuit breakers, disconnectors, instrument transformers, surge arresters, post type insulators, string insulators, batteries, battery chargers, protection, control and operating systems, telecommunication systems, etc. The paper shows the problems related to the criteria for choosing the new equipment, its technical specifications, and the works of replacing the old equipment with the new existing one. All the works is to be done considering that these substations must be in function, during the whole period of rehabilitation and upgrading.