ISLANDING DETECTION SYSTEM AND METHOD

An islanding detection system and method for multiple inverters(131,170) operating in parallel, wherein the multiple inverters(131,170) at least comprises a first inverter(131) and a second inverter(170) connected in parallel. The islanding detection system comprises a first current detection circuit(140) arranged on a grid side or an AC side of the second inverter(170); and a controller(132) connected to the first current detection circuit(140) and the first inverter(131). The controller(132) determines whether to perform distributed islanding detection or centralized islanding detection on the first inverter(131) and the second inverter(170) according to a grid voltage signal and a current detection signal of the first current detection circuit(140). By recognizing the islanding detection mode of the second inverter(170), matching it with typical islanding detection modes preset in a library, and determining to perform a distributed or centralized islanding detection according to matching results, the application improves the success ratio of islanding detection.