Dynamic System Performance Analysis of a Novel Grid Connection Topology for Offshore Wind Farms using MMC-HVDC Transmission

Large amounts of offshore wind energy are planned by the Dutch government for the next years. The power system will continue to evolve to integrate these new sources of green power efficiently. The dynamic system performance of a grid topology with transmission capacity above 1 GW connecting offshore wind farms (OWFs) at distances close to 100 km in a standardized and modular manner is the focus of this paper. An electromagnetic transient (EMT) model was built in PSCAD in which OWFs are connected with 66 kV cables to a centralized offshore platform and a transmission link with a capacity of 1050 MW. The connection to the onshore transmission network is through a high voltage direct current (HVDC) link that uses a modular multilevel converter (MMC) topology. A dynamic performance analysis with several expected operational cases is done to obtain a complete overview and understanding of the system.