Multi-time Scale Fault Characteristics of HVDC-Connected Offshore Wind Farm and the Coordination with Different Protection Schemes: A Review

The high-voltage dc (HVDC)-connected offshore wind farm is a power electronic converter dominated power system. Yet, the highly controlled fault characteristics of converters could affect the efficacy of different protection schemes. This paper first gives an overview of the multi-time scale fault characteristics of converters and the related different protection schemes. Then, the coordinated fast-time scale fault control of converters with the corresponding protection relays is summarized. Lastly, the protection schemes in slow-time scale are investigated, then the modified settings and criteria for these protection schemes are proposed considering the converter fault dynamics.