Abstract:
This paper describes the application of the abrupt change detection technologies to detect the abrupt changes in the signals recorded during disturbances in the electrical power network of South Africa for monitoring the relay performance. Main focus has been to estimate exactly the time-instants of the changes in the signal model parameters during the pre-fault condition, after initiation of fault, after circuit-breaker opening and auto-reclosure of the circuit-breakers. After segmenting the fault signal precisely into these event-specific sections, synchronization of the different digital fault recorder (DFR) recordings are done based on the fault inception timings. This is essential as the timebases of the DFRs triggering for the same disturbance are not perfectly synchronized. The synchronized signals are segmented again and the synchronized, segmentations are used to analyze the performances of the protective relays during the disturbance.