Abstract：In order to solve the DC over-voltage problem caused by surplus power when short circuit fault

occurs in the recipient grid of offshore wind power via voltage source converter high voltage direct current

transmission（VSC-HVDC）delivery system，a joint fault ride-through strategy based on surplus power allocation of

dissipation devices and offshore wind farm voltage reduction control was proposed. Firstly，the mechanism of DC

over-voltage of the VSC-HVDC system caused by power imbalance was analyzed，and the main influencing factors

of DC over-voltage were extracted. Secondly，the input power and output power relationship model of the VSCHVDC system was constructed to allocate the surplus power of the system without measures and optimize the

resistor resistance of the energy dissipation device based on it. Then，the fault ride-through strategy was proposed

based on the design strategy of energy dissipation resistor in conjunction with the voltage reduction operation of the offshore wind island and the technicality of the energy dissipation device was analyzed. Finally，the effectiveness of the proposed control strategy was verified on PSCAD/EMTDC. Simulation results show that the proposed control

strategy can solve the problem of DC overvoltage in the VSC-HVDC system caused by short-circuit faults at the

receiving end of the grid，avoiding the risk of offshore wind power being disconnected from the grid via the VSC-

HVDC grid-connected system due to short-time faults.

      Key words：offshore wind power；voltage source converter high voltage direct current transmission（VSCHVDC）；fault ride-through；dissipation device；island control；surplus power