Operation and Control of HVDC-Connected Offshore Wind Farm

This paper presents operation and control strategies of an offshore wind farm interconnected to a high-voltage dc (HVDC) system. The offshore wind farm composed of variable speed wind turbines driving permanent magnet synchronous generators is considered in this study, based on dc-bus concept. The HVDC transmission system based on a three-level neutral point clamped voltage source converter (VSC) is used for the interconnection between the offshore wind farm and onshore grid. Detailed modeling and control strategies are developed for the individual component of the overall system. A simple fuzzy logic controller is adopted in the offshore VSC station, which is one of the salient features of this study. Real wind speed data is used in the simulation study to obtain realistic response. Both dynamic and transient analyses of the proposed system are carried out using the laboratory standard power system software package, PSCAD/EMTDC.