Dynamic studies on HVDC-OWF systems - Impact of WTG on HVDC performances

Transmission connections to offshore wind farm (OWF) typically consist of multiple technologies supplied by different manufacturers each tested separately at the factory, but there is no composite modelling and testing capability currently available in Great Britain, for complex designs and combined solutions. This paper provides an overview on control sensitivity of the dynamic performance of an HVDC-OWF system. A generic but realistic HVDC-OWF test case is used. In order to study the impact of OWF on HVDC dynamic performance, four WTG models (generic and manufacturer black-boxed models) are simulated in the EMT-type tool. In addition, frequency response of the HVDC-OWF system after load rejection is studied to show the importance of control coordination between HVDC and OWF control tuning and the need of combined solution to ensure good performance and stable system. This discussion in turn highlights to both manufactures and vendors the critical areas of compliance demonstration needed across devices and their considerations. It illustrates the need for “sandbox” design and test environments to be established where a projects' designs are respectively defined and combined across devices at various points within the detailed design, individual factory test and commissioning phases of a projects' life-cycle.