Comparison of VSC based HVDC and HVAC interconnections to a large offshore wind farm

The integration of large offshore wind farms to the relatively small Irish transmission system is challenging, one major concern is fault ride through capability. To reflect this the Irish grid code has recently been modified to include new requirements on transmission connected wind farms. In this paper, a large offshore wind farm is modelled using DIgSILENT PowerFactory simulation package. The wind technology used is active stall regulated wind turbines driving fixed speed asynchronous generators. Two different types of interconnections are modelled and compared, a voltage source converter, VSC, based HVDC link and an AC cable interconnection. Transmission faults are simulated in each system, the response examined and results presented; particular attention is given to the fault ride through capability of each system.