Abstract:To explore the applicability of traveling wave fault location in half-wavelength transmission line (UTL), based on the amplitude attenuation feature and the reflection and refraction characteristics of the travelling waves, the critical fault distance within which the single-end traveling wave method can be applied is estimated. Then, the impacts of traveling wave distortion on traditional traveling wave fault location in the UTL are investigated, and a novel fault location scheme applicable to UTL is proposed. In the scheme, an additional measuring point is mounted in the middle of the line, and the polarity of the current traveling wave at the point is used to detect the fault section. The single-end or double-end traveling wave method is selected to pinpoint the fault in the determined fault section. An UTL simulation model is constructed by PSCAD/EMTDC and various fault simulations are conducted. The results indicate that the critical fault distance for single-end fault location is about 100~240 km. The proposed scheme eliminates the dead zone of fault location and shows high accuracy. In addition, the fault condition, tuning network, and load condition barely have any impact on the scheme, which demonstrates its high reliability.