Fault location of multi-point hybrid transmission line based on HHT

Abstract

Due to the discontinuous wave impedance, uneven line parameters, and complex and changeable fault transient traveling waves of overhead-cable hybrid transmission lines, the traditional double-ended traveling wave ranging method will produce large errors. Aiming at this problem, this paper proposes a fault location method for multi-point hybrid transmission lines based on Hilbert-Huang transform (HHT). First, the effective identification of the traveling wave head is completed at both ends of the line and at the connection point between the overhead line and the cable line, and then the HHT is used to extract the time when the fault traveling wave head reaches the measurement point, and finally it is substituted into the multi-point ranging equation to calculate the fault. The result of the ranging. The simulation results of MATLAB/PSCAD show that the method proposed in this paper avoids the influence of traveling wave velocity on the ranging accuracy, and is not affected by the line structure. Compared with the traditional double-ended ranging method, its ranging accuracy is higher. At the same time, it can also meet the requirements of engineering practice positioning accuracy within 200m.

Keywords

• able-overhead line hybrid transmission line
• hilbert-huang transform (hht)
• fault location
• traveling wave