Impact of reduced system inertia on stable power system operation and an overview of possible solutions

This paper provides a general overview of system inertia and its impact on the transmission grid stability. In the main part of the paper different solutions that provide frequency response have been analysed. Both conventional and alternative solutions have been described and their technical parameters have been presented. It has been shown that the available energy and maximum available power for the initial inertia response are limited in case of conventional generators. On the contrary the alternative solutions providing synthetic inertia (SVC PLUS Frequency Stabilizer and battery storages) are limited only by the amount of the energy stored and their rated power. It has been shown that from the technical as well as from an economic and environmental point of view the SVC PLUS Frequency Stabilizer and battery storage can provide the needed synthetic inertia in order to mitigate large frequency deviations. Furthermore, on comparing the SVC PLUS Frequency Stabilizer and battery storages it has been shown that for short time applications in range of several seconds (typical duration before the primary response starts) the SVC PLUS Frequency Stabilizer has significant economical and footprint advantages over battery solutions. This is mainly due to application of the supercaps as short time power storage technology.