A Novel Frequency-RoCoF Islanding Detection Method for Grid-connected Distributed Generation

Abstract

Based on the relationship between active power shortage and rate of change of frequency (RoCoF), combined with the load frequency characteristic, this paper derives the transient calculation formula of frequency and RoCoF after islanding occurrence in the grid-connected distributed generation system, and gives the setting principle of parameters in RoCoF islanding detection method (IDM). On this basis, a Frequency-RoCoF islanding detection method is proposed and its non-detection zone is calculated. The simulation results verify the accuracy of calculation formula of RoCoF and the feasibility of Frequency-RoCoF IDM.