Analysis of the variables influencing inter-area oscillations in the future Great Britain power system

The integration of power electronics (PE) interfaced resources in electrical power systems has been growing continuously. In future power systems, PE-interfaced devices, including renewable energy resources (RES) and High Voltage Direct Current (HVDC) technologies, are going to play a significant role in providing electrical energy. Therefore, the study of power system stability in mixed AC/DC networks is of critical importance. A significant number of wind and HVDC technologies will be connected to the Great Britain (GB) network by 2030, which makes the network an interesting study into the stability of mixed AC/DC networks with high numbers of PE-interfaced sources. In this paper, a reduced-order model of the future GB network is developed and used as a study case to explore the factors influencing the damping of an inter-area oscillation. The system variables are measured and a new measure, the centre of inertia (COI) electrical distance, is developed based on graph theory concepts to quantify changes in network topology. Then, correlation analysis is performed between these indices and the damping ratios of an inter-area oscillation. The results show that the new index, COI electrical distance, has a strong correlation with the damping of inter-area oscillation under changes in the network topology, which can be used for quick identification of potentially problematic operational scenarios.