A single pole to ground fault location method for HVDC transmission lines based on coupling characteristics

In this paper, coupling coefficient between conductors is demonstrated as a superior indicator for single pole fault location. A method is proposed to locate faults via estimating the coupling coefficient with the help of single end current measurements taken within the first mille-second after the fault created wave reach the terminal. As the coupling coefficient is not dependent on fault resistance, the single pole fault location can be done with the help of pre-calculated inverse coupling coefficients estimated for some metallic faults applied at regular intervals. The performances of the proposed single end fault location scheme are evaluated in long bipole line commutated converter based HVdc transmission system as well as in a medium length monopole HVdc transmission configuration. Higher accuracy is observed despite of simplicity of the proposed scheme.