Power-flow for archipelago-based multi-terminal HVDC grids

The development of multi-terminal HVDC (MTDC) grids for an archipelago of islands with very different generation/load profiles and network characteristics presents unique challenges. This paper utilizes the superposition theorem to solve power flows in MTDC grids. Through the application of the theorem, it is possible to associate the current/power injection at each terminal to voltage variations in the entire MTDC grid in a simple manner. Afterwards, this information is used to compare the impact of droop characteristics, to show how voltage variations relate with the injections from the different terminals and to study the impact of grid expansion on the operational limits. Additionally, the method is used to implement a power-flow optimisation and to design a droop characteristic for an imaginary MTDC grid connecting Indonesian islands. A discussion on other potential applications of the method is also put forward.