Saizhao Yang

TL;DR: A fault identification method based on the difference of square of transient voltages to identify the faulted lines for DC grids using overhead lines and a line protection scheme including detection activation, fault identification, faulted pole discrimination, and post-fault re-closing is designed.

TL;DR: The state-of-the-art of dc fault protection methods of MMC-HVdc grids are reviewed, and the underlying principles of each method are summarized, which direct the protection design.

TL;DR: An adaptive reclosing scheme based on the active pulse injection from the converter associated with the coordination control of hybrid DCCBs and the location of faults can also be achieved in the case of permanent faults is proposed.

TL;DR: An artificial neural network (ANN)-based method to enable DC bus protection and DC line protection for DC grids and the effectiveness of the proposed method in fault identification and the selection of the faulty pole is verified.

TL;DR: An improved dc fault protection algorithm using the modal-domain approach for the MMC-based overhead dc grids, which decouples the interaction between positive and negative poles and mitigates the strong frequency dependence of the characteristic impedance in phase-domain.