Verfahren zur Bildung eines Resistanzwertes

摘要

The invention concerns a method of calculating the resistance of a conductive loop formed by a fault in a monitored section of an power-supply line through which a.c. current is flowing, the method using instantaneous values of the current and voltage measured over a given period of time. In order to obtain the resistance as quickly as possible, the invention calls for instantaneous values of the current (IS(tn)) and the voltage (US(tn)) to be measured over a half-period (T2 omega ) of the a.c. current and instantaneous values of a power to be calculated from them. The instantaneous values of the power are integrated to give a value (Peff(tn)) proportional to the effective power. In addition, the instantaneous values determined for the current are squared and the integral (I<2>/ SIGMA (tn)) of the square of the current calculated. The resistance (R(tn)) is calculated by dividing the value (Peff(tn)) proportional to effective power by the integral (I<2>/ SIGMA (tn)) of the square of the current.