A novel double-ended fault location identification scheme for multi-terminal HVDC grids based on Hilbert-Huang transform

Accurate identification of fault location in multi-terminal HVDC grids contributes to reducing the downtime of the faulted segment and determining critical locations frequently exposed to fault incidents. A double-ended fault location identification scheme for multi-terminal HVDC grids is proposed in this paper based on Hilbert-Huang Transform (HHT). First, HHT is utilized to extract the instantaneous frequency and energy from voltage measurements. Then, a setting-less criterion based on outlier detection is employed to capture the arrival time of the initial fault-induced backward traveling waves. Based on the arrival instants at line terminals, the fault location is identified with high precision. The proposed scheme can locate high-resistance faults up to 1000 Ω within 1 ms. Various simulations are executed to demonstrate the accuracy and reliability of the proposed scheme.