Method for calculating the fault point distance to a single-pole earth fault within an electric power network

摘要

The first step (21) is to measure line to earth voltages (UR,US,UT) and currents (IR,IS,IT) and the zero sequence voltage (UO) and current (IO). In step (22) the symmetrical voltage (U0,U1,U2) and current (I0,I1,I2) components of the three sequence systems are calculated by transformation of the above values. In step (23) the symmetrical zero sequence current and the fault current (IF) are calculated. ??The above steps are repeated for a different neutral to earth impedance. In step (24) differential values are formed from the two sets of values from which in step (25), the fault distance and resistance are calculated.