A Fault Ride-Through Method Based on Energy Dissipation Device in the Scenario of Flexible HVDC Grid Connection of Offshore Wind Power

The flexible HVDC transmission technology based on the modular multilevel converter (MMC) topology has a very broad application prospect in the process of large-scale renewable energy collection and transmission. This technology has become one of the best choices for long-distance offshore wind power farms to connect to the onshore power grid. In view of the special working conditions such as overvoltage in the fault state, this article proposes a controllable large-capacity self-recovery energy-dissipation device for the first time to improve the transient characteristics of the DC and AC power system. The proposed scheme has the advantages of no harmonic generation during operation, relatively simple control strategy and high current impact resistance. The electromagnetic transient simulation shows that the proposed scheme can effectively solve the overvoltage problem of DC in the offshore wind power flexible HVDC system, and improve the reliability of the HVDC system.