The equivalent models of voltage source converter based high voltage direct current(VSC-HVDC)are described. The model of the negative sequence directional component is built

and the adaptability of the negative sequence directional component applied in the hybrid power grid of VSC-HVDC and AC power grid is analyzed in theory. The theoretical analysis is verified by simulation and suggestions for protection configuration are provided. The theoretical analysis and simulation results demonstrate that the positive and negative current decoupled controller can restrain negative fault current and have a good performance in fault ride through. The negative sequence directional component may refuse to trip when the AC power grid is unbalanced. The negative sequence directional component is inapplicable to the outgoing line of VSC-HVDC station. This work is supported by China Southern Power Grid Company Limited(No. GZ2014-4-0006).