An overview of anti-islanding detection algorithms in photovoltaic systems in case of multiple current-controlled inverters

Grid-connected distributed generation power systems (DGPS) based on inverters require the employed controller to include an islanding detection algorithm in order to determine the grid status and operate properly. In certain cases, such as low-power low-cost current-controlled inverters used in residential photovoltaic (PV) systems, the inverter must be stopped once the islanding condition is detected according to the standard and grid-code limits. Passive, active and monitoring-based algorithms for islanding detection have been analyzed in literature considering one DGPS connected to the local electrical power system (EPS). Only in case of active methods, such as active frequency drift (AFD), the effect of two DGPS in the same local EPS on the islanding capabilities has been analyzed. This paper analyzes the performance of diverse passive and active islanding detection methods (IDM) in multiple inverters connected at the same local EPS interact.