Analysis of the Probable Decrease of Load Shedding Reserve in Power System of Ukraine at Installed Capacity of Renewable Energy Sources

Abstract

Analysis of system emergencies in European power systems, which have a share of renewable sources in the generation structure, revealed the shortcomings of the under frequency load shedding (UFLS). An important fact of this was that UFLS disconnected at the same time part a load of demand together with the generation that was in the network of Distribution System Operator (DSO). From the analysis of emergencies, it was possible to conclude that if there is a share of distribution generation (DG) in the power system, it is necessary to take into account this feature when choosing the amount of load shedding (LS) and setting of UFLS relay. The paper conducted research to determine the reasons for the reduction of the UFLS reserve on a single line diagram of the local network with the connected solar power plant. The current UFLS scheme, which uses relays with and without time delay, was investigated and was offered an optimal scheme.