Frequency Converter Topology Research in Flexible Low-Frequency AC Transmission System Applied to Offshore Wind Power Transmission

Flexible low-frequency AC transmission (LFAC) technology can be used for offshore wind power transmission. Compared with high-voltage alternating current (HVAC) transmission and high-voltage direct current (HVDC) transmission technology solutions, LFAC has its unique advantages. This paper studies three topologies for LFAC inverters, namely BTB-MMC, M3C, and DRU-MMC. And compared and analyzed, M3C is recommended as the topology of the frequency converter in the offshore wind power transmission scene at the present stage. This paper also gives the topology scheme of the transmission system for offshore wind transmission and access to the power grid under the LFAC technology, which provides a reference for subsequent engineering implementation.