METHOD OF DETERMINING FAULT OF POWER SYSTEM

A method of determining a fault of a power system comprises: estimating, based on measured electrical quantities at a first position of a power line in the power system, voltages at a second position of the power line, the measured electrical quantities being associated with three phases of the power system and comprising voltages at the first position of the power line (601); determining at least one phase angle between the voltages at the first position and the estimated voltages at the second position (602); and detecting the fault based on the at least one phase angle during a power swing (603). In the method according to the present disclosure, a three-phase fault during a power swing is identified in a shorter time, and thus the tripping is performed with a faster speed, thereby improving stability and safety of the power system.