International Journal of Engineering and Innovative Technology (IJEIT)
It is well known that sometimes Protective Relays (PRs) malfunction and trip the Circuit Breakers (CBs) giving a wrong signal of what has actually happened. There were several analytical models for fault diagnosis each having its own limitation to address the possible malfunction possibilities leading to an incorrect diagnosis. Based on these models, a new analytical model was developed to take into account of the possible malfunctions of PRs and CBs and further to improve the accuracy of the fault diagnosis. This model does not only estimate the faulted sections but also identify malfunctioned PRs and CBs.