Model Recognition Based Arc Extinction Time Recognition Strategy for True Bipolar Flexible HVDC Systems

Transient single-pole grounding faults are the most probable faults on transmission lines. To optimize the reclosing time of transient faults, it is necessary to identify the fault arc extinction time. Firstly, the time-domain expression between the electrical quantity and the traveling wave at both ends of the line is derived by analyzing the frequency-dependent model. Secondly, based on the idea of model recognition, the non-fault model is used as the calculation model. The actual models before and after the transient fault arc is extinguished are different, so the difference between them and the calculation model is also different. Finally, the Pearson similarity is used to extract the above-mentioned differences, and a strategy for recognizing the arc extinction time of a single-pole grounding fault in true bipolar flexible high voltage dc (HVDC) systems is proposed. PSCAD/EMTDC simulation results verify the effectiveness of the proposed strategy.