East Anglia is an area of comparatively low demand and net export to the wider transmission system area that already features a range of generation technologies, both conventional and power electronic sources. In the transition to Net Zero, there is expected to be nuclear power remaining alongside a significant increase in power electronic connections; the largest contributions coming from offshore wind and interconnectors in the area.
There are several parts of GB where offshore wind farms will connect through new HVDC links. With converter stations in close proximity, performance of each individual project at its onshore connection point is likely to depend on overall performance of all projects and their interaction with the rest of the power system.
The National HVDC Centre conducted a study to explore possible control system interaction risks between multiple HVDC converter stations. The studies used the PSCAD software to build suitable models of the network area of interest with the new HVDC converter stations and conduct a range of studies to assess interaction risks. The purpose of the work was to identify risks and possible mitigations in a time frame suitable to inform project designs.
This project applied and helped improve the HVDC Centre’s tools and methods for small signal analysis, especially the use of dynamic frequency scanning techniques in PSCAD to produce impedance characteristics and the interpretation of those results in assessing interaction risks. The project was delivered in close collaboration with the wind farm developers, helping to ensure the analysis and outputs met their needs. The work was completed with a presentation of results to the Transmission Owner and System Operator by the HVDC Centre and the involved wind farm developers. This project demonstrated how the analysis methods honed at the Centre can be applied to help tackle some of the biggest technical challenges facing the industry.