A New Whole-Line Quick-Action Protection Principle for HVDC Transmission Lines Using One-End Current

HVDC transmission systems have found wide applications in modern power systems and have produced a useful influence on the stability and security of power systems. The currently used protections for HVDC systems operate on the principles which have poor reliability and inadequate sensitivity. To overcome these problems, this paper presents a new whole-line quick-action protection principle for HVDC transmission lines. The proposed method, based on the boundary characteristics of the line, can distinguish internal faults from external ones using single-terminal current measurements only. The criterion of this protection has been formulated. Simulations on frequency-dependent parameter-line model and the field-recorded data of a 500-kV HVDC system show that this method is valid and feasible. The proposed protection, sound and clear in principle and easy to implement, can be expected to become a primary protection of HVDC transmission.