Method and control system for fault direction detection

Abstract

A method for detecting fault direction of transmission line of an AC power system and control system using the same. The method includes: sampling current values and voltage values of three phases at one end of the transmission line for a series of time points; for each of the series of time points, computing instantaneous symmetrical voltage components of the three phases based on the voltage value samples for the respective one of the series of time points; for each of the series of time points, computing instantaneous symmetrical current components of the three phases based on the current value samples for the respective one of the series of time points; for at least two of the series of time points, calculating energy directional elements each based on the respective ones of the computed instantaneous symmetrical voltage components and the respective ones of the computed instantaneous symmetrical current components; identifying the fault direction in consideration of the calculated energy directional elements; and generating a fault direction signal indicating the identified fault direction. Simulation results show the graph of the energy directional element calculated based on instantaneous symmetrical voltage components and instantaneous symmetrical current components exhibits distinctive characteristics either for forward or reverse fault. In consideration of such difference, by calculating the energy directional element at each sampling time point, the fault direction information may be identified accurately.

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