Restoration islands supplied by gas turbines

The paper describes how gas turbine based plants (open cycle and combined cycle) can be profitably used in power system restoration for supplying restoration areas. In recent times, in fact, several gas turbine sections entered the power system due to the improved efficiency of gas turbines and to the development of high efficiency combined-cycle plants. These units can be easily improved to provide black-start capability and can therefore largely increase the black-start capacity of the entire system. Restoration islands to be used for minimizing the time to supply critical areas, such as urban and industrial zones, can support the usual restoration paths designed to provide cranking power to large steam units. The paper presents the defining criteria for the procedures to be followed during restoration. An example referred to as an urban area is reported with simulation results. The Italian System Operator recently carried out some tests on an open cycle gas turbine aimed at checking the island operation of the unit. Some results are described.