Multi-terminal DC grid control under loss of terminal station

In this paper, the operation of Voltage Source Converter (VSC) based multi-terminal DC (MTDC) transmission system is evaluated under loss of converter station. From the control point of view, i) Master/Slave control method, and ii) droop control method are explored to control the multi-terminal DC grid. This paper compares different control methods for MTDC control under normal and loss of any terminal station. Also, a droop control structure with dead-band controller is proposed for MTDC grid control. The dynamic performance of a four-terminal DC grid is further investigated in PSCAD/EMTDC environment. Simulation results are presented and compared to demonstrate the superior performance of the proposed control method during loss of a converter station.