The system of determining the fault connection in the distribution network

The authors have developed a method for determining the fault connection with the single-phase earth faults in medium voltage networks with isolated or compensated neutral. Determination of the fault line in medium voltage networks is a complex problem in technical terms due to highly branched network. High accuracy of the proposed method is based on the resonance voltage phenomenon. There is a significant current increase in the fault connection in the resonance mode if compared with current in the line without fault. Resonance is provided by applying high-frequency current from an additional source of sinusoidal voltage connected to the mains. The principles of practical implementation of the device determining the off-line connection are presented. The developed method has been tested in a real electric network. The tests have proved stability and reliability of the off-line determination with single-phase ground fault.