Method for detecting line to line fault location for power systems

PURPOSE: A method for detecting a point of short circuit between lines in a power supply system is provided to infer the distance of the point of short circuit by analyzing directly a three-phase circuit. CONSTITUTION: A method for detecting a point of short circuit between lines in a power supply system includes an impedance, current, and voltage acquisition process and a trouble point distance calculation process. The impedance, current, and voltage acquisition process is to detect the line impedance and the load impedance by expressed complex numbers and obtain the phase voltage, and the phase current at an installation position of a relay. The trouble point distance calculation process is to calculate the distance of the trouble point by using a relational expression obtained from the multiplication of the trouble voltage and the trouble resistance.