Traveling wave-based fault location formulation for hybrid lines with two sections

In this paper, the mathematical development of a traveling wave (TW)-based fault location scheme for hybrid transmission lines (HTLs) with two sections is presented and evaluated. The formulation is able to accurately estimate the fault point on HTLs taking into account the different propagation velocities on each section. In order to carry out the proposed studies, the Alternative Transients Program (ATP) was used to simulate various fault scenarios in a 220 kV/50 Hz test power system, considering different fault distances in a HTL consisting of an overhead transmission line in series with an underground high voltage cable line. In each case, the obtained fault location result is compared with the fault distance estimation computed using a traditional two-terminal TW-based fault location method. The obtained results show that the evaluated fault location formulation is accurate and easy-to-use.