Time Base Zero Crossing Directional Overcurrent Protection Relay

Abstract

Conventional fast fourier transform directional protection relay requires complex butterfly computation overheads and memory buffers. In this work, the directional function is realized by using time base zero crossing method. The time base zero crossing directional method is simulated in a configuration of a parallel medium voltage feeder circuit, and by modeling fault current in the cable between the generation and load. The zero crossing method requires less computation and memory space, as a result it responds faster in comparison to fast fourier transform method. Furthermore, it is also easier to program in a real time hardware system. The result from the simulation shows that both directional overcurrent and normal inverse current relay coordinate successfully when fault current is introduced to different length in the cable.