ISLANDING DETECTION METHOD FOR DISTRIBUTED GENERATIONS INTERCONNECTED WITH UTILITY NETWORKS

摘要

PURPOSE: A method for determining an exclusive operation of system interconnection distribution power is provided to increase a reliability of the method by reducing an erroneous operation of an electric measuring members caused by various reasons. CONSTITUTION: A voltage and a current are detected(S10) at a point interconnected with a distributed power system. A voltage imbalance index is calculates(S20) from the voltage and the current. A voltage imbalance change index is calculates(S40) by using the voltage imbalance change index. Whether the voltage imbalance change index exceeds a predetermined value is determined(S50). Distributed powers are determined to operate in an islanding mode and a trip signal is transmitted(S100) when the voltage imbalance change index is larger than the predetermined value.