The rapid development of large-scale offshore wind power (OWP) calls for more cost-effective and reliable collection and transmission technologies. This paper explores three emerging collection technologies: medium-frequency alternating current (AC) collection, direct current (DC) collection, and AC collection without substation; and three transmission technologies: voltage source converter-based high-voltage direct current based on compact modular multilevel converters (MMCs), diode rectifier unit (DRU) based high-voltage direct current (DRU-HVDC), and high-voltage direct current (HVDC) based on hybrid converters. It systematically reviews recent research advancements in these technologies, analyzes critical technical challenges, and identifies key future development trends, providing practical insights to guide the design and optimization of OWP projects. At the collection level, a higher frequency reduces the size of critical equipment in offshore platforms but also leads to increased cable costs. DC offshore wind farms offer advantages such as lower cable costs. However, the design of high-power DC transformers presents challenges. At the transmission level, the size and weight of MMCs can be minimized through topology improvement and control optimization. The practical deployment of DRUs and HVDC systems depends on the technology maturity of grid-forming wind turbines. More-over, critical aspects of hybrid converters such as capacity design, coordinated control, and stability analysis require further in-depth investigation.
Huangqing et al. (Thu,) studied this question.