Comparative Study of Low-Frequency Transmission Solutions for Offshore Wind Farms

The use of low-frequency ac (LFAC) technology emerges as a competitive and viable solution for the integration of offshore wind farms. This paper provides a comparison of the typologies and control strategies employed in two LFAC transmission schemes. The first scheme involves grid-following controlled offshore inverter with onshore grid-forming controlled rectifier, while the second scheme employs grid-forming controlled offshore inverter based on reactive power synchronization with onshore uncontrolled diode rectifier and ac filters. In this paper, the steady-state operational performance of two low-frequency ac transmission schemes with back-to-back structures is comparatively analyzed in terms of power flow and power quality aspects by simulations.