The Novel Method for Determining Locations of a Double Ground Fault in Networks with Isolated Neutral

Abstract

The problem of determining locations of a double ground fault in networks with isolated neutral is much more complicated due to a topographic remoteness of faults places. The necessary level of perfection of the novel method for determining locations of such faults is ensured through the use of many algorithmic network models. The general algorithmic model of the network is used to calculate the voltage at the supposed place of a fault. Algorithmic models of an undamaged network and models of a pure fault regime allow dividing electrical quantities into components, related only to the measured voltages at the installation location of the device, and into components that are completely determined by the fault currents. Such property of the models allows the algorithm to be theoretically independent of short circuit resistances. An important role in fault locations is played by the hypothesis of the resistivity of the ground fault circuit. Following this idea, the new algorithm uses an objective function to fault location on the line, which is a measure of the transmitted reactive power in the transverse circuit between phase and ground. The stability and accuracy of the algorithm do not depend on the remoteness of faults places from each other.