AFD방식을 이용한 단상 계통연계형 PV시스템의 단독운전시 계통주파수 변동 특성 해석

To detect islanding mode when the grid is being tripped is a major safety issue in utility interactive PV(UIPV) system. And one of the widely used techniques to detect islanding mode are Reactive power variation (RPV)method and Active frequency drift (AFD)method. In this paper, analytical design method is suggested for AFD method under IEEE recommended islanding test condition. And in order to show the validity of proposed method, EMPT based simulation was done for UIPV system with AFD method. Results shows proposed method is very useful.