Review of Lightweight Oriented Offshore Wind Power Transmission Schemes*

The use of renewable energy is essential for addressing global climate change, and offshore wind power plays a critical role in achieving this goal. As nearshore resources become saturated, the focus of offshore wind power development is shifting to deep-sea areas. Deep-sea wind power transmission schemes must prioritize lightweight designs and low costs to enhance overall economic and technical feasibility. Currently, four lightweight offshore wind power transmission schemes have been identified: low-frequency alternating current (LFAC) transmission, high-voltage direct current (HVDC) transmission utilizing uncontrolled diode rectifier units (DRU-HVDC), DRU-MMC parallel-connection hybrid rectifier transmission (PCDRU-MMC), and DRU-MMC series-connection hybrid rectifier transmission (SCDRU-MMC). Four schemes are examined, advantages and disadvantages in various scenarios are outlined, technical performance are analyzed. A comprehensive economic assessment of each scheme is conducted for deep-sea environments far from load centers. The results indicate that LFAC transmission effectively reduces transmission losses, whereas DRU-HVDC has limitations in terms of voltage support and black-start capability. In contrast, hybrid rectification solutions such as PCDRU-MMC and SCDRU-MMC combine the economic benefits of DRU-HVDC with the flexibility of modular multilevel converters (MMCs), thereby enhancing system reliability and efficiency.