Two-terminal Fault Location Method Based on the Lines Converted Midpoint and HHT

Aiming at the problems of travelling wave’s speed velocity discontinuity problems in the hybrid transmission line composed by cables and overhead lines, a new method of two-terminal fault location based on the converted midpoint of the transmission line and HHT is presented in this paper. First, the hybrid transmission line was reduced to a single parameter line to get the midpoint of the line. Then, the HHT (Hilbert- Huang Transform) was used to detect the travelling waves’ heads. The search direction of the fault was calculated according to the time difference