Comparing secondary voltage regulation and shunt compensation for improving voltage stability and transfer capability in the Italian power system

This paper concentrates on comparing the advantages and disadvantages, including costs, of using secondary voltage regulation (SVR) versus using shunt-connected controllers, in particular mechanical switched capacitors (MSC), static var compensators (SVC) and static synchronous compensators (STATCOM), to improve voltage stability (VS) and the external transfer capability (TC) of the Italian power network. Basic VS and TC concepts and tools, as well as the models of the various controllers, particularly SVR, used to obtain the results presented are described in detail. The model of the Italian system used and the assumptions made for these studies are also discussed. The paper demonstrates that SVR is an option that should be seriously considered in practice when trying to improve VS and TC of power systems.