A Traveling-Wave Detection Method Based On Redundant Wavelet Transform Applied to Three-Phase Transmission Line Experimental Test Bench
Fault-induced transients, traveling waves, wavelet transform, transmission line protection, fault detection and location.
Traveling-wave detection methods have been widely studied in recent years due to the implementation of traveling-wave-based protection and fault location schemes applied to transmission systems since they are faster and more accurate than traditional schemes employed by power companies. Researchers have been developed traveling-wave detection methods by using the most varied digital signal processing techniques. This work proposes a traveling wave detection method, based on redundant wavelet transform, and applied to experimental data, which is extracted from a three-phase transmission line. The proposed method utilizes high-sampling frequency to detect the first incident wavefront, even as the subsequent ones due to reflections at line terminals and at fault point. The experimental test bench is composed of a three-phase alternate current source, a one kilometer long four-wire polypropylene-type flexible copper cable, which enables the traveling-wave propagation phenomenon, a load resistance, and fault resistance. The fault switching is realized by pressing a push-button. Currents and voltages are measured by means of transducers connected to one of the line terminals, the fault point, and an oscilloscope. Therefore, fault transient signals are acquired, stored, and can be offline analyzed. Handling this setup, it is possible to control the distance that fault occurs, the fault type, as well as the fault resistance and the fault incidence angle.