摘要

A novel method of fault identification for dc line based on the correlation of transient current is proposed to improve the fault-handling ability of VSC-HVDC transmission system. The difference of the transient current at parallel capacitor branch and dc line entrance is significant between the internal and external fault of dc line. Pearson correlation coefficient is used to measure the difference between the transient currents, by which the fault identification can be achieved easily by calculating the correlation coefficients at both ends of the faulted line. The proposed method is able to eliminate the influence of the contribution from non-faulted line and it is suitable for two-terminal and multi-terminal VSC-HVDC system. The results of the analysis and the simulations show that the proposed method is able to identify the internal and external faults of dc line and select the fault line accurately without the influence of high-frequency component, data synchronization, fault types and fault location, noise interference and the control mode of VSC-HVDC system.

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