Experimental testing of distance protection performance in transient fault path resistance environment

This paper present an experimental comparison study of the distance protection operation during metallic earth faults, earth faults with constant fault arc resistance and faults with constant fault arc resistance and additional transient ground path resistance. The aim of this study is to recreate “in vitro” conditions when distance protection maloperated during fallen tree fault. Such earth faults are more common in the region and they are known as “weak points” of distance protection. The tests were performed by simulating the faults in MATLAB SimPowerSystems environment. The obtained transient waveforms of currents and voltages were then comtraded to ISA TDMS system, via which the output signals, provided to the digital relays, were generated. As a result an environment for testing of distance protection performance during fallen tree faults was created. This provides an opportunity to find possible errors of the existing distance protection algorithms and develop more robust ones.