In Scotland, to mitigate the consequences of frequent system anomalies in a remote area of the network, the Distribution Network Operator (DNO) decided to integrate a Battery Energy Storage System (BESS) into the Drynoch primary substation, enabling the downstream network to operate in islanded mode. The aim of the research is to analyse in depth the behavior of the network once the BESS has been installed. To do this, a load-flow analysis and a short-circuit analysis have been implemented on an approximate network model of the real network. Both analyses have been carried out for different load, generation and operation conditions.