Fast pilot protection method based on waveform integral of traveling wave

摘要

This paper proposes a fast pilot directional protection based on waveform integral of traveling wave for high voltage transmission line. Within a very short time of post-fault, the waveforms of positive and negative direction traveling waves are integrated, respectively, and their relevant ratio is calculated. According to the propagation characteristics of traveling wave, an operation threshold is set. If the ratio value is less than this threshold, the fault direction is thought as positive; otherwise, if the ratio value is higher than this threshold, the fault direction is negative. Through comparing the identification results of fault direction from two terminals of the protected line, the internal fault or external fault can be determined rapidly. To test the protection performance, an ultra high voltage (UHV) transmission line model was constructed and the extensive simulations were performed. The theoretical analysis and simulation results show that the proposed protection technique can fast and reliably discriminate the internal faults from external faults. Generally, the performance of protection is hardly influenced by the fault resistance, fault inception angle and busbar configuration, etc.