An efficient algorithm for fault detection by directional overcurrent relay based on current waveform in distribution systems

Abstract

Considering the growth of distributed energy generation systems in distribution networks, quick and precise protection and at the same time low cost is very perceptible. This protection includes directional relays beside overcurrent relays. The directional relays in the network require voltage and current relays; therefore, the cost of using this type of protection in the distribution network is very high. This is the reason that in directional relays operation only using current sensor can be a proper choice. This paper presents a simple and quick and at the same time efficient algorithm which is used to detect the fault from rising the current slope and determining the direction of the fault current from Lissajous curves. Simulation results based on the introduced algorithm are presented.