Islanding detection technology for a photovoltaic grid-connected power system

Anti-islanding protection is mandatory feature for grid-connected inverters.Desired islanding detection methods not only can detect islanding within acceptable duration,but also require lessening adverse impact on power quality.The occurrence causes and negative effects of the islanding were presented.The non-detection zone,applied scope,influence on power quality and transient response of every method were discussed.Finally,it is indicated that further enhancing of the detection efficiency,diminishing and even eliminating the non-detection zone on the basis of reducing the influence on the system and the combined use of several islanding detection methods based on different principles will become the focuses of future researches.