A Novel Hybrid Islanding Detection Technique for PV-Battery DC Microgrid

A hybrid islanding detection technique for a DC microgrid is presented in this paper, in which a novel passive index (cumulative product of superimposed voltage) is proposed for disturbance identification in the first stage (passive). The second (active) stage discriminates between islanding and nonislanding disturbances and is activated if the proposed passive index exceeds a threshold. The computation of the proposed passive index is simple, requiring only voltage measurements, making the proposed approach fast and easily implementable. Simulation studies verify that the proposed technique can successfully discriminate between islanding and non-islanding events, quickly detect islanding under zero power mismatch scenarios, and improve power quality.