DC grid system behavior: A real-time case study

The overall system behavior of a three-terminal DC grid with symmetric monopole configuration is the focus of this paper. The modeling of the DC grid test system which includes converter stations, hybrid DC breakers, cables, etc. is carried out in real-time digital simulator (RTDS) platform. For control and protection, ABB´s MACH system is used. Some important system aspects of DC grid, e.g. AC fault-ride-through, clearing of DC faults through hybrid DC breakers, post-fault re-dispatch of power through master control and elimination of DC voltage unbalance are demonstrated in this paper through real-time hardware-in-the-loop simulations.