Design and hardware implementation of a modular transient directional protection scheme using current signals

This study presents the concept, implementation and test results of a fault direction identification method that applies to identify faulty segments in transmission systems. This method relies on the wavelet analysis of the transient currents. Exchange of fault direction information among intelligent electronics devices located at different locations of network permits identification and isolation of the faulty network segment. A prototype of the fault direction identification unit was implemented using a floating point digital signal processor platform. The performance of the prototype was tested with current signals generated using a real-time waveform playback instrument. The transient waveforms were obtained from an extra high-voltage transmission system simulated in electromagnetic transient-type simulation program. Investigations were carried out under different scenarios such as current transformer saturations, measurement noise etc.