- TRANSIENT PROTECTION FOR MULTI-TERMINAL HVDC GRID

摘要

The present invention discloses a method and device for providing protection of a multi-terminal HVDC grid from failures. The method includes the steps of measuring a DC displacement voltage (Ud) having a polarity and a value, determining whether a short circuit fault exists by comparing the DC displacement voltage (Ud) with a threshold displacement voltage (Ut) And identifying the fault type based on the value. The disclosed device includes a converter having an anode and a cathode, a DC-switch substation, a DC line connecting the converter and the DC-switch substation, and a transient fault detector. The transient failure detector includes a positive voltage sensor for sensing the positive transient voltage Up of the positive polarity and a negative voltage sensor for sensing the negative transient voltage Un of the negative polarity and a negative voltage sensor for sensing the positive transient voltage Up, And derive a DC displacement voltage (Ud) from the input voltage (Un).