Investigation of active islanding detection methods in multiple grid-connected converters

As the development of distributed generation technology, the renewable energy resources are widely transformed to electricity and transferred to the utility through grid-connected converters. Islanding detection is a mandatory function for the converters. It usually injects perturbations to the converter output to improve the effectiveness of islanding detection. The current research is mainly based on individual converter, while the islanding detection strategies in multiple grid-connected converters operation are investigated in this paper. The characteristics of commonly used active frequency drift and active phase shift islanding detection methods in multi-inverter systems are explored. The design principle of the two islanding detection strategies and the corresponding parameters selection rule are also presented. It provides a basic guidance for the islanding detection design in multiple grid-connected converters.