Approach to faulted line impedance calculation

In the case of a fault on electric power system line even basic frequency component of the fault current has rather complex form consisting of constant amplitude member and members with amplitudes attenuated with different time constants. Taking into account that there is a possibility to eliminate DC and harmonic components in electric signals during a fault in acceptable short time period, it was shown here that the rest of the signal can be used for (fast) line impedance calculation with acceptable accuracy. Calculations and testing based on here presented approach with real generator parameters and for all kinds of faults show that error in resulting impedance value was always less then 3%, qualifying the method as acceptable for technical applications. Method of faulted line impedance calculation was referred.