Travelling Wave Based Directional Relaying Without Using Voltage Transients

In this letter, an alternative solution for travelling wave based directional relaying scheme is presented by utilizing the prefault voltage sample acquired at a much lower sampling rate along with current travelling wave. There is no requirement of voltage travelling waves for the method. The performance of the proposed method is evaluated for faults simulated on a 400 kV transmission network which reveals its advantage for faults when change in voltage signal is low. The proposed method is independent of the transient response of the capacitive voltage transformer.