Key Technologies and Grid Integration Challenges of Low-Frequency AC Transmission for Offshore Wind Power

Offshore wind power is a critical renewable energy source. It benefits from stable wind resources, proximity to coastal load centers, and efficient land use. However, integrating largescale (hundreds of megawatts) and medium-to-long-distance (over 70 km) offshore wind farms is challenging. Low-frequency alternating current (LFAC) transmission at 10–20 Hz offers a promising solution. It combines the simplicity of AC circuit breakers with reduced cable charging power and higher transmission capacity. This paper explores LFAC key technologies and grid integration challenges, focusing on system configurations, AC/AC converter topologies and fault ride-through strategies. Taking the Yuhuan No.2 project as a case, an energy dissipation device on the M3C low-frequency side is validated via real-time simulation, maintaining system stability during a single-phase fault. LFAC shows remarkable mediumdistance advantages. Future research should focus on multi-terminal networking, lightweight equipment and collaborative control between wind turbines and conversion valves. These advancements will support future gigawatt-scale projects.