Research on Fault Ride Through Strategy of Multi-terminal HVDC Considering Offshore Wind Clustering Effect

The integration of large-scale offshore wind power located far away from the onshore grid can be realized through multi-terminal high voltage direct current (HVDC) technology. However, power surplus problem of isolated wind power connected to multi-terminal HVDC caused by direct current (DC) fault is easy to result in the system overvoltage and trip-off accidents of wind turbine. Firstly, the fault ride through (FRT) performance of multi-terminal HVDC system is studied, and the influence of power surplus on DC voltage is investigated. Secondly, based on the marine scenario, the configuration method of DC chopper considering the clustering power characteristics of offshore wind power and power conversion control of HVDC is proposed. And then, the FRT control strategy based on DC chopper configuration method is further determined. Finally, simulation on offshore wind power integrated by three-terminal HVDC is carried out to verify that the proposed FRT strategy contributes to the fast recovery of offshore wind power delivery system via HVDC grid.