Advanced transmission, control, fault ride-through, and protection strategies for offshore wind farms using VSC-HVDC systems: An integrative review

This article presents an integrative review of offshore wind farms connected via high-voltage direct-current (VSC-HVDC) transmission systems based on voltage-source converters. This review focuses on power transmission technologies, wind turbine converter interfaces, VSC-HVDC system architectures, control strategies, fault ride-through (FRT), and protection standards. Particular attention is given to modular HVDC systems based on multilevel converters, multi-terminal DC networks, and the interaction between converter control and protection design. Conventional, nonlinear, predictive, intelligent, and robust control strategies are compared in terms of stability, dynamic performance, FRT capability, and protection system coordination. The review also discusses fault behavior on both the AC and DC sides, DC fault protection, fault current limitation, selective fault isolation, and post-fault recovery. The scalability of offshore multi-terminal DC grids, control–protection co-design, real-time validation, cybersecurity, and techno-economic optimization are among the major unresolved issues that are finally identified. The paper highlights that future offshore VSC-HVDC systems should be designed using an integrated transmission-control-protection approach to provide reliable, secure, and cost-effective integration of large-scale offshore wind power.