Offshore wind power flexible direct current control method under receiving-end power grid fault

The invention discloses an offshore wind power flexible direct current control method under a receiving-end power grid fault, and the method comprises the steps: enabling an onshore converter to obtain a three-phase modulation wave signal under a power grid fault condition through a power control link in a control mode of combining reactive power control/AC voltage control and DC voltage control; performing positive and negative sequence separation calculation on the three-phase modulation wave signal to obtain a zero-sequence injection component, and obtaining a modulation wave direct-current injection amount by combining the output of a circulating current controller and a zero-sequence component superposition amount; and finally, obtaining a new three-phase modulation wave signal by using the direct-current injection amount, and controlling the turn-off and turn-on of the on shore converter so that the voltage peak value of the sub-module is reduced, and the transmission capacity of the flexible direct cur