Increasing the Efficiency of Operation of Fault Indicators at Long-Distance Branched Overhead Lines

The paper presents the method of increasing the efficiency of operation of fault indicators at long-distance branched overhead lines by using resistance neutral grounding. In the case of ground faults at overhead lines, which are usually operated in Russia with ungrounded of resonant grounded neutrals, low ground fault currents flow through line branches. It is difficult to identify such low currents by conventional means. It is proposed to use resistance neutral grounding not only for the purpose of overvoltage limitation at arcing single phase-to-ground faults with elimination of restriking ground faults at other phases, resonance and ferroresonance phenomena, but also for ensuring correct operation of fault indicators. It was verified by simulations using MATLAB/ Simulink that a resistor current flowing in the faulty overhead line branch increases sensitivity of fault indicators.