Reactive power control method and device of high-voltage direct-current power transmission system

The invention discloses a reactive power control method and device for a high-voltage direct-current power transmission system, and the method comprises the steps: calculating the speed drop amplitude of direct-current current needing reactive power control according to the reactive power demand of the high-voltage direct-current power transmission system during steady-state operation, and calculating the speed drop amplitude of the direct-current current needing reactive power control according to the rated reactive power and real-time reactive power provided by reactive power resources; the method comprises the following steps: determining a direct current dynamic adjustment amount required to be subjected to reactive power control, calculating a direct current rated current based on direct current rated transmission power of a high-voltage direct current transmission system and a direct current voltage under a no-load condition, and adding three calculated current amounts to obtain a reactive power control