METHOD FOR DETERMINING FAULT DIRECTION, OVERCURRENT PROTECTION AND DISPLAYING FAULT INDICATION IN DISTRIBUTION SYSTEM WITH DISPERSED GENERATION

摘要

PURPOSE: A method for determining a fault direction of a distribution power connection line, an overcurrent protecting method, and a fault display method are provided to prevent the malfunction of a protection device due to a backward fault current. CONSTITUTION: A three-phase current is inputted(S302). The phase of the inputted three-phase current is calculated(S304). A phase difference between phase currents is calculated using the phase of the three-phase current(S306). A fault direction is determined by comparing the phase difference between the phase currents with a preset threshold value(S308-S312). [Reference numerals] (AA) Start; (BB) Three-phase current input; (CC) Three-phase current phase calculation; (DD) Phase difference calculation; (E1,E2) Yes; (FF) Reverse direction; (G1,G2,G3) No; (H1,H2,H3) Forward direction