776 / 2019-04-28 17:44:47

Transient Current Single-Ended Protection for HVDC Lines Based on Complete Ensemble Empirical Mode Decomposition with Adaptive Noise

HVDC; DC line protection; Single terminal；Transient voltage; border protection

Aiming at the problems of high sampling rate of single-ended protection for traditional HVDC lines and neglecting the influence of transmission lines on the attenuation characteristics of transient signals, a single-ended protection scheme of transient current based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is proposed. Through the analysis of transient current characteristics in different fault areas of DC lines, it can be concluded that there are significant differences in the frequency characteristics of transient current between the internal and external faults when the faults occur in the positive direction. Using CEEMDAN algorithm, the maximum frequency natural mode function imf1 of transient current is obtained, and the maximum instantaneous frequency is extracted by Hilbert transform to form a boundary protection element. Combining the starting element, directional element and polar selector, a single- ended protection scheme is proposed. The simulation results show that the scheme can operate correctly under various working conditions, has strong resistance to transition resistance, high reliability and good adaptability.