Role of multi-infeed VSC-HVDC on dynamic behaviour of future north Scotland transmission system

Due to the expected proliferation of HVDC systems up to and beyond 2020 into the Great British transmission network, it is anticipated that in some locations two or more HVDC converter stations will be installed with only a short electrical distance between them and will form a multi-infeed (MI)- HVDC system. This is a particular concern in the North of Scotland. This paper investigates the impact of MI-HVDC links on the North Scotland system for two different system generation mixes. A list of control schemes has been formulated to assess the dynamic performance of the developed realistic system under typical loading scenarios. The work has been conducted in a DIgSILENT Power Factory using case study simulations of the integrated North Scotland system model. From the set of case studies, it has been found that the AC voltage control allocation within the HVDC links has a significant influence on the smalldisturbance angle and transient voltage stability of the system.