Performance evaluation of active anti-islanding scheme for multi-inverter DG systems

Islanding detection is an essential function for safety and reliability in grid-connected distributed generation (DG) systems. Several methods for islanding detection are proposed in literature, but most of them may fail in multi-source configurations, or they may produce important power quality degradation when the DG penetration is high. This paper presents theoretical analysis and evaluation of an active anti-islanding protection algorithm for Voltage Source Inverter (VSI) multi-source DG systems proposed in previous work. Particularly, this paper presents an evaluation of the anti-islanding scheme considering: different multi-inverter topologies, the effect of transmission line length and the effect of the measured variations of utility voltage.