Special protection scheme for operation of central Zagreb transmission system

The paper presents a Special Protection Scheme solution for the central Zagreb transmission system. The central Zagreb transmssion system is a charaterized by a highly meshed network with combined overhead and cable sections and a special operation of the 110 kV cable link between two power plants important for the citys heat and electricity supply. The Special Protection Scheme is developed using static and dynamic analyses of different network scenarios. Island operation is simulated for a consumption and generation surplus, and an underfrequency load shedding scheme is determined. The Special Protection Scheme architecture is presented with a brief description of the telecommunication infrastructure.