Optimal DC Voltage Control in Multi-Terminal HVDC Network: Modeling and Scenarios

Efficient and balanced power transfer with minimum transmission losses in Multi-Terminal High-Voltage DC (MTDC) network is managed by the hierarchical control layers. A combination of decentralized DC voltage droop control and centralized Optimal Power Flow (OPF) controller can maintain the MTDC network power flow with minimum power losses. This paper presents scenarios of droop-controlled radial MTDC network with the objective of minimizing the DC grid transmission losses supported with average value modeling and optimization approach. The droop characteristics are tuned for effective power-sharing among the receiving nodes. The OPF controller maintains the network operation within the allowed operational constraints during normal network operation (i.e., in case of variable power injection to the MTDC network. The simulation results of the MTDC network average value modeling and OPF are presented with the aid of the Matlab/Simulink platform.