Controlled Islanding with Vsc-hvdc Links Acknowledgements

Controlled islanding has been widely discussed in the literature as a novel concept for the power system protection. However, the islanding can result in unbalanced islands where the power mismatch will often cause an instability that can lead either to a subsequent load shedding or generator tripping within the islands. Controlled VSC-HVDC links can mitigate the negative consequences of the controlled islanding by allowing active power transmission between the islands. Moreover, VSCs can assist in controlling the voltage within the islands. This thesis shows that the controlled VSC-HVDC links can support the controlled islanding by stabilising the islands in terms of frequency and voltage. For this purpose, we extend the existing K-means clustering based controlled islanding algorithm [KCVA10] so that it can provide an islanding solution in which the islands are interconnected by the VSC-HVDC links. Moreover, we introduce a simple control scheme for the VSC-HVDC links that allows to use them for stabilising the islands. We simulate the controlled islanding to show the effectiveness of the proposed algorithm and the control scheme.