An offshore wind farm with DC grid connection and its performance under power system transients

The continuous increase in wind power penetration level brings new requirements for wind turbine integration into the network. The grid code requires that after clearance of an external short-circuit fault, grid-connected wind turbines should restore their normal operation without power loss caused by disconnections. This paper presents a transient performance study of an offshore wind farm with HVDC transmission for grid connection, where the wind turbines in the offshore wind farm are also connected with dc collection network. A power-reduction control strategy (PRCS) for transient performance improvement is proposed for the offshore wind farm that allows it to withstand severe voltage dips. A simulation model of a 400 MW offshore wind farm developed in PSCAD/EMTDC is presented. The transient performance of the offshore wind farm is studied, and the results show the effectiveness of the proposed control strategy.