Method and System for a pilot directional protection of LCC-HVDC lines based on virtual grounding resistance

The application relates to a method and system for a pilot directional protection of LCC-HVDC lines based on virtual grounding resistance The method comprises: Obtaining a conduction state information of a converter and characteristic parameters of a converter circuit within one commutation period after a fault occurs; according to the conduction state information and characteristic parameters, determining characteristic frequency of the circuit; according to the characteristic frequency and characteristic parameters, determining a virtual grounding resistance; according to the virtual grounding resistance, determining fault areas.